Category Archives: Rules

Mettle rules graft v0.1

This is a hack that integrates an alternative partial-success d20 resolution system and replacement health system. The original posts on some of these ideas:

The primary design priority is fluent ease of use.

For me, this is essentially subsystem playtesting (for my ongoing, slow-burning Hexagram project), but I think this could be useful as a mod also.

(See the downloads page for a PDF version.)


Necropraxis Mettle Rules Graft

Start with something like B/X D&D, Labyrinth Lord, or Lamentations of the Flame Princess and then suture in the following systems and rules. This is a draft playtest document and I assert no compatibility.

Tests

  • Resolve uncertain actions using the test procedure (1d20 +modifier), interpreting the result as follows:
1 2-9 10-15 16-18 19+
Hindrance & Catastrophe Hindrance Progress & Hindrance Progress Progress & Triumph
  • Tests replace attack rolls, ability checks, and saving throws
  • If the unmodified result is 1 or 19+, ignore the modifier

Basics

    • Moves are actions with predefined sets of potential test outcomes (see combat, below, for examples)
    • Add proficiency bonus to class-relevant tests given proper equipment
      • Weapons for fighters, lock picks for thieves, wands for magic-users, and so forth
    • Proficiency bonus follows 5E: = ceiling(level / 4) + 1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
+2 +2 +2 +2 +3 +3 +3 +3 +4 +4 +4 +4 +5 +5 +5 +5 +6 +6 +6 +6

Gear & Equipment

  • Characters have 25 gear slots: 5 panoply, 4 hand, 6 belt, & 10 pack
    • Panoply slots correspond to hit locations: 1 head, 2 legs, 3 arms, 4 abdomen, & 5-6 body
    • The 4 hand slots are primary (left, right) & secondary (left, right)
    • Place any additional gear in burden slots (burden imposes penalties)
  • Each gear slot has a uses track with up to six boxes
    • The uses track represents wear and tear or uses remaining
    • Gear determines the max uses: quiver of arrows (6), sword (3), and so forth
    • When the number of marked boxes equals the max uses, gear is broken, ruined, or used up

Magic

  • Spell slots = level + 2; each slot has uses = proficiency bonus
  • During haven turns, cast spells from grimoires
    • Other magicians can tell when spells are active
  • After casting a spell, magicians can cause effects using the invoke move
    • +INT for black magic, +WIS for white magic
    • To add proficiency bonus when invoking, equip a focus, such as a staff or wand
    • When invoke test outcomes include hindrance, mark a spell use

Combat

  • Peril—such as monster attack—results in death unless an action forestalls such fate
  • The block and dodge moves replace opponent attack rolls
  • The endure and suffer moves replace taking damage
    • Mettle = level +CON
    • To mark mettle, mark a number of hearts = opponent threat (HD, level, or whatever)
    • If directed to mark mettle when none remain, make the suffer move to avoid death
    • Dying characters expire at the end of the current round
  • Sprain and fracture conditions disable the relevant hit location
    • 1 = head, 2 = legs, 3 = arms, 4 = abdomen, 5-6 = body
  • If a character is already bleeding and the condition comes up again, the character bleeds out and dies
  • Armor bonus applies to the endure move
    • Light armor = +2, medium armor = +4, heavy armor = +6
    • Proficiency: fighter = heavy, thief = light, wizard = none
    • Characters are burdened if wearing armor without proficiency
  • Two-handed weapons provide advantage for strike, shields provide advantage for block
Approach Moves Strike Shoot Maneuver
Prerequisite Melee equipment Weapon & ammo Situational
Modifier +STR +DEX +STR or +DEX
19+ 2 hits 2 hits Attain objective & 1 hit
16-18 1 hit 1 hit Attain objective
10-15 1 hit & mark use 1 hit & mark ammo use Attain objective & mark use
2-9 Endure Mark weapon use Endure
1 Endure & mark use Mark weapon & ammo use Endure & mark use
Avoidance Moves Block Dodge Endure Suffer
Prerequisite Melee equipment Unburdened
Modifier +STR +DEX +Armor +CON
19+ 1 hit Position & 1 hit Recover 1 Recover 1
16-18 Position Sprain
10-15 Mark use Position & lose balance Mark use Fracture
2-9 Endure & mark use Endure & lose balance Mark use & mettle Bleeding
1 Endure & mark use Endure & mark use Suffer Dying

Spell book dilemmas

Image from Wikimedia commons

Magic systems can treat spells more like things one knows or more like things one has. That is, skills versus possessions. This is not a pure dichotomy, and various systems draw from both approaches. There is, however, a fundamental trade-off in moving along this continuum from magic as skill to magic as possession. A skills approach leads to more focused, mechanically simple, and niche-protected characters within a party. A possessions approach leads to more flexible, mechanically complex, and interchangeable characters within a party.

Skill versus possession makes the biggest difference in systems that strictly regulate skill development through acquisition of levels. Traditional D&D and similar games generally work this way. I think a more fine-grained system, such as Burning Wheel skills that develop based directly on fictional actions, would also exhibit this dynamic, but it probably would make less of a difference. In the options below, I assume skills and possessions function close to traditional D&D.

I am thinking about magic systems right now, so this is more a descriptive post to help me organize my thoughts than a proposal for a particular approach. I am curious about pushing the magic system closer to the possessions end of the spectrum while still maintaining distinctiveness between magic-using characters within a party.

Option 1: Pure Skill

In this approach, knowledge of a particular spell is like a learned skill. Characters learn new spells only by engaging character improvement mechanics directly (such as level-up) rather than through fictional actions (such as picking up a wand). Sharing spells between player characters is either impossible or costly. (See also this older post on strict spell learning.)

Perhaps surprisingly, playing B/X by the book treats spells mostly like skills for magic-users (see page B16 and this post by Alex). Magic users gain new spells on level up and there are no other rules for learning spells apart from the expensive spell research rules in the Expert rules, which require 1000 gp per spell level and seem to be intended for newly invented spells, not other spells in the existing catalog (see page X51). Apart from the research rules, spell memorization in B/X is fictional logic wrapped around a resource management fire and forget game mechanic.

Pros: simplicity, high character distinctiveness within party

Cons: can feel more like super powers, collecting spells through adventuring less emphasized

Option 2: Spell Learning

One method that takes a step toward spells as possessions is having a set of spell book rules that include systems for learning spells outside of character improvement mechanics. A magic-user can only memorize spells from a personally written spell book. This spell book or books can contain any number of spells, but copying a spell into the book requires a special action and perhaps some cost, to prevent the easy replication of spells within a party, which would give all magic-users access to the same spell list. Then, magic-users choose which spells to prepare from the book, up to level-based limits, during downtime.

AD&D popularized this approach. The AD&D rule for attempting to learn a spell is to make a percentile chance to know spell check, which is based on intelligence (AD&D Players Handbook, page 10). Characters that fail this check may never learn the spell in question. This naturally leads to spell lists unique to each magic-user. In my experience, players hate rolling to learn spells with the possibility of never being able to learn a particular spell, so though this system has some nice emergent properties, it can be a difficult sell.

Some more recent systems, such as ACKS repertoires and 5E spell slots, seem like variations on this approach, but constrain which known spells are available for actual use in play. Such constraints provide a small brake on the tendency for magic-using characters to accumulate spells without limit. Though these systems often seem superficially logical (at least to me), they also are rather complex to explain and can require extensive bookkeeping. For example, the 5E approach to spell books requires players to manage separately the spells in the book from the spells available to cast (5E Basic Rules, page 30) and spell slot implementation is, on reflection, nine different kinds of mana/spell points for for players to manage.

Pros: spell book atmosphere, moderate character distinctiveness within party, magic-users adventure to collect more spells

Cons: bookkeeping, higher chance of copying spells between player characters, often less player influence over the kind of spells learned

Option 3: Possession Plus Access Skill

Magic could also be entirely located within a possession but require a skill (or something like a skill) to use the possession. That is, a character would need something like a necromancy skill to use necromancy type magic items but such as skill would grant access to all such magic. (One could make the taxonomy of magic as fine-grained as desired to increase the likely distinctiveness of magic-using characters.) Though only intended to supplement the primary method of casting spells for characters, the traditional rule of only allowing characters belonging to the magic-user class to use stereotypically wizardly items is a crude version of this kind of approach.

A simple version of this that might work well is to take specialist rules and turn them on their head. Rather than assume generalist magic-users have access to all spells, with specialists giving up access to several schools of magic in exchange for increased power with a focal school, instead assume that generalist magic-users have no access to any spells other than those of known schools. In this way, proficiency with a school of magic would become similar to proficiency with a class of weapons, as implemented in 5E D&D.

Pros: concrete magical atmosphere

Cons: requires a skill system for acquiring access to spell schools, somewhat nonstandard, spells within school easily shared between characters

Option 4: Pure Possession

On the far end of the spectrum, the ability to cast a spell could entirely depend on character possessions. The way to get access to the fireball spell is to find a wand of fireballs (or whatever). There are various ways to place some restrictions on exchangeability, such as 5E attunement or traditional class features, but such rules often feel artificial, obviously twisting setting elements to solve a game problem.

Into the Odd uses this approach. There are not really any spells in the traditional sense and instead magic powers reside in arcana, which any character can use. I believe some arcana require something like a will save and many are consumable.

Perhaps surprisingly, given how this can sometimes lead to magic feeling like technology in a game context, it is actually closer to how magic often works in mythology and fantasy fiction. For example, Robert Howard’s sorcerer Thoth-Amon derived most or all of his magic from the serpent ring of Set. Arguably, magic in Vance’s dying earth stories sort of works like this, as non-magician characters sometimes memorize spells, though it is possible that such characters still have some sort of special talent or skill. For game purposes, this would be close to a pure gear approach.

Pros: simplicity, flexibility

Cons: characters feel less like archetypal wizards, low character distinctiveness within party


There are probably many other variations, but I think these examples illustrate some common approaches and the trade-offs that come with choosing a particular place on the rules continuum.

It is worth noting that these dynamics exist across classic classes as well, with thieves being more skill based and fighters being more possession based. For example, only thieves know how to use lock picks while fighters can usually trade weapons, though various approaches to proficiencies and so forth can change how this works. However, distinctiveness feels more important to me for magic-using character types than for mundane character types. I suspect this is true for others as well. (Explaining this feeling is perhaps a topic for another post, hopefully written by someone other than me.)

Maybe relevant: grimoires for OD&D

Ryuutama miscellany

Following are a few miscellaneous mechanical ideas gleaned from Ryuutama which may be worth adapting or hacking into your D&D-alike edition of choice.

Initiative is AC

At the start of combat in Ryuutama, each player character rolls initiative, which is DEX + INT. Recall that abilities are dice, with d6 representing average, so this roll is something like 2d6 or d6+d8. The value obtained both determines order of action and defense value (basically, AC). An equipped shield provides a minimum defense value (7 for small shields and 9 for large shields). This makes both initiative and shields more influential without contributing to numerical inflation (as happens with the arms race between AC bonus and attack bonus for many versions of D&D).

In addition to equipping a shield, player characters can use an action to re-roll initiative, taking the new result if it is better. So, a bad initiative roll does not spell doom, though it can slow a player character down (which seems appropriate for initiative).

Initiative also controls retreat

Even among those woke to the virtues of morale checks, in my experience it is easy to slip into fighting to the last combatant. This may play into the reasons for retreat rules either being somewhat complex or perhaps just untested. In any case, the Ryuutama approach here is both simple and surprisingly harsh when followed to the letter, given the suggested heartwarming tone. The rule is that travelers can retreat if the sum of their initiative values is equal to or higher than the sum of enemy initiative values. This means that once enemies gain an advantage, it may become very difficult, or even mathematically impossible, to run away.

That math may be less than ideal, depending on your intention for combat dynamics, but I like the idea of using initiative to manage retreats. Another, slightly more flexible approach for Ryuutama along similar lines—that I may use the next time I run Ryuutama—would be to have the entire party make a new group initiative check to determine whether running away is possible. This would hold out a sliver of hope, even if several travelers were down and the sum of enemy initiative values was high.

This is even easier to hack into another game if using side-based d6 initiative, though it is a bit more random. When the player characters win initiative they can simply declare retreat and it happens, as long as there are no obvious fictional constraints such as a bridge being out. Similarly for monsters. Then, if one side or the other wishes to pursue, chase rules would come into play.

Battlefield abstraction

Ryuutama battlefield (PDF here)

As in many classic JRPG video games, combatants are either in the front or rear rank. Combatants in the front rank may be targeted with either melee or ranged attacks while combatants in the rear rank may only be targeted with ranged attacks. Any area effects attack all combatants in the front ranks, either allied or opponent. If all the combatants in the front rank are defeated, the remaining combatants in the rear move into the front, meaning that it makes sense to maintain several frontline defenders if possible, though one will hold the line.

This is elegant (and plays nicely based on my limited experience so far). The structure maintains enough tactical complexity to model offensive and defensive fighting without resorting to bonus math; further, it requires minimal bookkeeping. I was originally somewhat wary of the structure feeling artificial and constraining tactical infinity, but in practice our fictional battlefield and the tactical schematic coexisted without conflict. This approach could be lifted verbatim, I think, into a B/X game.

Ability checks draw on two abilities

In Ryuutama, any ability check uses two abilities. In all versions of D&D that I am familiar with, ability checks use only one stat, such as strength. Using two abilities leads to a surprising degree of mechanical richness, however, and would be particularly easy using the ability bonus scale of B/X, which is 13-15 = +1, 16-17 = +2, and 18 = +3. This, two relevant 18 stats yields only a +6 bonus, well within the scope of modern bounded accuracy approaches. This would be most straightforward when using roll high versus DC style ability checks but easy with roll-under checks too (just allow the bonus of one ability to increase the value of the other ability, for purposes of the immediate check).

Condition modulates poison etc

Traditional D&D often uses save or die for poison. This works well enough, but requires some care on the referee side. It is, however, abrupt. Many alternative approaches soften the blow by providing various additional buffers, such as having poison do damage or applying other effects. Generally, this makes poison either a mere distraction or an additional thing to track.

The approach in Ryuutama is to make poison, and other similar conditions, only affect travelers with condition less than or equal to some set value. (Condition in Ryuutama is sort of like mood and travelers re-roll it each day.) The effect of poison in Ryuutama is to decrease strength by one die type. A D&D analogue might be disadvantage to attack rolls and physical ability checks, with the modulating factor probably being HP; for the threshold, something like 25% or 50% max HP might work. Though this certainly makes poison less immediately terrifying than save or die, I kind of like it.

Stronghold achievements

A Kingdom Death settlement phase

One dynamic I have noticed with XP = GP spent is that there is a great incentive for players to spend money primarily on short and medium term goals. This is largely positive, in terms of gameplay, as it results in PCs spending their GP quickly to gain levels, and thus needing to get back to adventuring to get more GP, which is a virtuous cycle from the perspective of generating adventure.

However, there is an implied endgame in many versions of D&D where adventurers build strongholds, accumulate followers, and possibly transition into a game of domains. Where do the resources for building a stronghold come from if adventurers continually squander recovered treasure? One could abstract this process, simply granting adventurers a stronghold at sufficient level, or expect players to think ahead, saving GP as necessary. In any case, most campaigns end far before adventurers attain such elevated levels, so an alternative and perhaps more practical approach would be to integrate domain game systems into lower levels.

Exploring this idea, I see an opportunity to both ground such as system in the party as aggregate, rather than the individual adventurers, and perhaps build the entire advancement system around the creation and development of adventurer bases. That is, rather than gaining levels from accumulating XP from killing monsters, recovering treasure, or completing quests, why not gain levels based on establishing strongholds? Mechanically, the highest level of stronghold possessed by the adventuring company could determine individual adventurer level as well. That is, to attain second level, the party must purchase a company clubhouse. Even if one were not inclined to push the idea that far, systematizing and simplifying the implied domain game in a way that is accessible to adventurers of all levels may be useful.

Below are draft details for levels 1 through 5. Levels 6 through 10 are haven, stronghold, cultural fountainhead, colony, and capital. I may similarly detail the later levels in a future post. (Cultural fountainhead needs a better name but is intended to represent building libraries, temples, archives, or something like that.)

  1. Tavern hangout (in lawful haven)
    Recovery: 5 GP per adventurer per haven turn
    Reputation: scoundrels available for odd jobs
  2. Clubhouse (in lawful haven)
    Adventurers possess their own private space in a haven.
    Requirement: 5000 GP purchase price
    Recovery: free each haven turn
    Reputation: adventurers
    Habitants: at least one or two attendants or stewards, along with off-duty retainers
    Dangers: competing adventurer companies
  3. Hideout (in chaotic wilderness)
    A hideout is a small, unobtrusive lair liberated from forces hostile to civilization. Lawful hunters, trappers, and other travelers help ensure that the hideout is self-sufficient and provide regular news and exchange.
    Requirement: lair liberated from a faction of chaos
    Recovery: free each haven turn
    Reputation: established freebooters
    Habitants: several stewards plus visiting traders, minstrels, or travelers
    Dangers: evicted faction becomes dedicated foe, monster attacks
  4. Outpost (in chaotic wilderness)
    An outpost is a fortification liberated from forces hostile to civilization. Once liberated, an outpost starts to acquire some trappings of civilization, including some permanently resident tradespeople. However, the area remains too isolated or dangerous for lawful settlers to call home permanently.
    Requirement: fortification liberated from a faction of chaos
    Recovery: free each haven turn
    Reputation: serious mercenary company
    Habitants: several enterprising craftspeople or merchants, stewards, travelers
    Dangers: evicted faction, military assault, monster attacks
  5. Settlement (in pacified, previously chaotic borderlands)
    Settlements are small, fortified villages. A settlement is stable enough to attract enterprising settlers seeking opportunity or a new start.
    Requirement: pacification of nearby borderlands (several hexes in all directions if using a hex map), 5 notable triumphs such as pirate kings defeated or significant monsters slain, 50000 GP investment in infrastructure
    Recovery: free each haven turn
    Reputation: governors or warlords
    Habitants: several permanent shops, traders, and craftspeople; several settler families
    Dangers: local lawful powers see the company as political risk

Adventurers must go through each step in sequence. Think of the collection of bases as an umbilicus stretching from civilization into the unknown. A hideout, for example, will only be self-sufficient through connections with the clubhouse in town. For this reason, adventurers retain all bases as they expand outward.

As the adventurers grow in reputation and stature, they naturally accrue a retinue and staff which enables and lives off the exploits of the company. The details of such organization may remain relatively abstract in terms of costs, though stewards, resident craftspeople, and so forth could be drawn from personages encountered by the adventurers during the game, such as rescued villagers or converted bandits.

What about adventurer death? New adventurers begin at level one, increasing one level for each session survived until they reach the current company level. Or, if that is too much bother, players could just make a new adventurer at the current level. Such parvenue adventurers would still need to accumulate gear and renown in the eyes of players.

The Ryuutama engine

A while back, I posted about the OD&D game engine. I think that post was helpful to me at the time for understanding how OD&D the game worked at a mechanical level. As I have been reading and enjoying Ryuutama recently, a similar exercise may be informative. This exercise may also provide a good intro to Ryuutama for players familiar with traditional D&D.

There are several broad, generally applicable rules systems: travelers, incentives, journeys, setting, combat, and the ryuujin. I will only focus on the first four of those systems here because they seem most integral to the core engine.

Travelers

These are the rules for player characters, which Ryuutama calls travelers.

Travelers have three major mechanical underpinnings: classes, type, and ability scores. Class in Ryuutama is more like background in many other games, and provides a set bundle of skills. Example classes are merchant, hunter, and farmer. Travelers get one class at first level and another at fifth level (max level is 10). Type, however, is more like what class means for other games, and can be one of attack, technical, or magic, which map, respectively, to the traditional classes of fighter, thief, and magic-user. There are four ability scores: strength, dexterity, intelligence, and spirit. Ability scores are measured in dice, with d6 seeming to be about average, d8 being one step higher, and so forth. Travelers also have three state variables: hit points, mental points, and condition (a value that fluctuates daily and is sort of like mood).

The major resolution system is the check, which involves rolling two ability dice (sometimes both are the same ability), adding the results, and comparing the sum to a target number (like a difficulty class in D&D terms). For example, accuracy with a blade (basically, rolling to hit, which is based on weapon type) is DEX + STR. Trapping, a hunter skill, uses DEX + INT. Target numbers range from 4 up. The text labels 7 as a little difficult and 12 as very difficult, to provide some orientation.

  • Class: artisan, farmer, healer, hunter, merchant, minstrel, noble
  • Type: attack, technical, magic
  • Ability scores: strength [STR], dexterity [DEX], intelligence [INT], spirit [SPI]

There are a few other details such as favored weapon, carrying capacity, and so forth, but the rules mentioned above are the foundational components. You can check out the full character sheet as well.

Incentives

Similar to most traditional fantasy games, characters increase in power through gaining levels, and gaining levels requires XP. Concretely, increasing level improves an ability, provides some extra HP or MP, and provides a few other perks depending on which level.

Ryuutama awards an amount of XP each session based on the highest topography target number (more on this in a moment) encountered, the single most powerful monster defeated, and for each benediction (GM-PC power) the referee used.

I like this approach overall because it rewards seeking out challenges and requires minimal bookkeeping. It is generally relatively easy to recall the single most powerful monster and there is no need to track the exact number of orcs or whatever. Further, though the marginal benefit may be small, the game will always reward tackling a more powerful monster or more dangerous environment within a given session.

Journeys

The journey procedure is a loop that the party engages to move from one fictional place to another. In sequence: condition checks, travel checks, direction check, and finally camping check. The final three checks all use terrain + weather as the target number. Each traveler makes a separate condition and travel check, but the mapper (one traveler designated by the party beforehand) makes a single direction check for the entire party. A single camping check applies to the entire party as well. The travel check is kind of a big deal, because failing it halves the traveler’s HP (which is about as important in Ryuutama combat as it is in traditional D&D combat, though the halving procedure suggests quite a bit more abstraction in Ryuutama compared to what many players assume about HP in D&D).

For each of these journey checks you end up rolling a pair of ability dice (added) versus an objectively determined target number; for example, grasslands = 6, deep forest = 10, strong wind = +1, and hard rain = +3. So, travelers journeying through deep forest in the hard rain will be rolling against a target number of 13.

Setting

Travelers journey between places and encounter things. What determines the details of towns, what lies between them, and what challenges relevant to the travelers exist?

Within the setting rules are guidelines for creating the world at a high level, towns, scenarios, and events. These rules are more elastic than other systems and read more like a set of suggestions than a tight set of procedures, though there are worksheets for each (town, world, scenario, event) with prompts, along with the invitation to maybe work through the process collaboratively with players. For example, the town worksheet has spaces for representative building and specialty goods.

Though not explicitly stated procedurally, several aspects of the rules gesture toward the idea of building up the world organically as journeys unfold, while leaving space for some more traditional lonely-fun referee world-building. There is a grid map sheet that players could fill in as travelers journey. The rules suggest an option where all the players design the town for the next session at the end of the current session and place it on the map, indicating what interstitial areas the referee should focus on in preparation.

Ryuujin

The ryuujin (GM-PC guardian angel) rules also seem important for running a game of Ryuutama in the expected mode, due to how they support the referee intervening in a limited way to shape the story. However, the ryuujin rules are tied less tightly to the core engine, as far as I can tell, apart from the XP reward for using benedictions as noted above, and so I will end here. See this post for a bit more on the ryuujin rules, if you are curious, and also the ryuujin character sheet.

Eidolon mode

Ryuutama mechanizes a limited degree of referee fudging through a conceit where the referee plays a character called the ryuujin. In translation, this means dragon person, and represents an entity somewhere between minor deity and guardian angel. The ryuujin exists within the fictional world, but in practice stays mostly offscreen. It is actually a character though, with a record sheet, life points, powers, level, and so forth, though the applicable rules for a ryuujin are different than those for player characters.

Mist dragon summon from Final Fantasy 4 (SNES)

In Final Fantasy 4, the character Rydia is a caller, a kind of magician that can summon Eidolons, or Call Beasts, to fight for the party. In Final Fantasy 6, espers are powerful magical entities that once defeated can be summoned. Systems exist for summoning in many Final Fantasy games.

Can you see where I am going with this?

A similar structure could be used for a powerful supernatural ally such as a bound demon, sandestin, or summoned creature. For players used to a more limited scope of narrative influence and narrower tactical challenge, the ryuujin rules can seem to be something between easy mode and cheating. However, that interpretation may be more driven by tone rather than mechanics. With slightly different flavoring, and possibly exposing more aspects of the ryuujin record sheet to the party as a whole, similar rules could support access to something like summoning an esper. Consider also the possibility for something like a mech or titan form (Attack on Titan, Voltron, etc).

Mechanically, Ryuutama gives the ryuujin several capabilities, including benedictions and reveils. Benedictions are powers that a ryuujin can use by spending life points and have effects such as rewinding a small amount of fictional time or declaring a particular check to be a critical success. Some benedictions create obstacles for players, such as increasing monster power or allowing an enemy to run away without needing to satisfy any conditions, presumably in support of guaranteeing certain story elements. In a reveil, the ryuujin appears in dragon form and saves the players in some specific way, such as manifesting to take the damage intended for a player character. Even when representing something like a summoned ally more under the control of players than is the ryuujin, the entity could maintain a degree of autonomy, also causing complications for players occasionally.

Evangelion / Voltron / Attack on Titan

Some of the ryuujin rules are attempts to mechanize a limited degree of referee discretion while maintaining some impartiality. Others are explicitly for rescuing and assisting the travelers, essentially decreasing the stakes in pursuit of the intended tone, which is low-arousal, calming, and heartwarming (honobono, in Japanese). However, with a slightly different set of priorities, similar rules could mechanize access to limited supernatural heavy artillery that players could deploy a few times per session.

Catastrophe magic

This is a magic system I have been testing. It is general enough that I think it should be easy to use with other traditional fantasy games, if you like, given a small amount of adjustment to the system you are using.

This is a roll to cast system. You need to decide on a set of known or prepared spells for a character. Then, the die outcome will take care of the resource aspect of spells. You also need a resolution system that provides five levels of outcome. You can think about these outcomes as levels of player character success or as augury into the fictional world. The five outcomes are:

  1. Principle intensified
  2. Principle
  3. Principle & corollary
  4. Corollary & decline
  5. Catastrophe & decline

The principle is the basic spell effect, the thing that the sorcerer is generally attempting to bring about. The principle intensified is the critical hit version of this. The corollary is an unintended side effect that generally complicates the magician’s life but may occasionally be useful. Decline represents a decrease in future spell potential or magical energy. The simplest implementation of decline is, following a Vancian approach, forgetting the spell. And finally, catastrophe is a total misfire which may have personally deleterious effects. This set of outcomes means that something magical always happens but the potential corollaries and catastrophes should make players think twice about playing with arcane fire.

To resolve the casting of a spell, I use an ability check, similar to the approach described here, with intelligence for black magic and wisdom for white magic.

For an approach closer to classic d20, consider the following:

Let target = 10 + spell level. Then, roll 1d20 and add spell bonus (something like one-half level, rounded up). Interpret the result as follows:

  • Natural 20: principle intensified
  • Target + 4: principle
  • Target: principle & corollary
  • Below target: corollary & decline
  • Natural 1: catastrophe

Further, you need a way to determine what each class of outcome means for a given spell. Writing new spells with extensive corollary and catastrophe tables is wonderful but by no means necessary.

Ideally, catastrophes are specific to individual spells, but lacking specific catastrophes, you can fall back to some general outcomes, such as these:

(I am sure there are others available too.)


Hacking a spell to support this system can be easy. For example, here’s a hack for the classic spell magic missile:

  • Principle intensified: +1 extra missile
  • Principle: as written
  • Corollary: an additional missile targets something non-animate (determine randomly)
  • Catastrophe: determine target of each missile randomly (friends and foes)

For many spells, it is feasible to rule on potential corollaries and catastrophes in real time. I would just clarify with the player what the potential scope of outcomes would be and confirm intention to cast the spell prior to the roll.


See also:

Mettle, trauma, and grit

For me, the ideal hit point or vitality system for tabletop roleplaying games involves the constant threat of engaging consequences while also mitigating the disastrous influence of luck. Using OD&D and sticking to the three little brown booklets comes close to this ideal when run in a certain manner, but still perhaps gives luck too much influence at first level and creates too much of a hit point buffer at mid to high level. Put another way, I want a system that encourages players to always care about combat consequences but rarely if ever shanks without warning. And, of course, the system must be fluent, easy to use, plugged in to the core flow of play, and require minimal bookkeeping.

Playing Kingdom Death gave me some ideas regarding ways to build a combat system that better prioritizes these goals, and that influence should be clear in the following sketch. As written, it may be too invasive to just trivially drop into a game using a B/X type engine, especially given that it requires replacing traditional armor class with ablative armor, but I think it would be possible.

Before anyone gets all up in my business about the dynamics of real armor or wounds, I want to emphasize that realism is a relatively low priority apart from maintaining predictable fictional consequences, necessary for allowing creative problem solving. Instead, the point is to create rules that facilitate choices and consequences while reinforcing the overall feel of the kind of survival fantasy that is my preferred mode for tabletop roleplaying games. This system assumes the turn structure of the Hazard System.


Section of the Hexagram character record sheet relevant to armor and mettle

Mettle

Rather than hit points, player characters have mettle, which can be both bound to hit locations (all player characters have this kind of mettle) or floating (for tougher characters, those with high constitution). Instead of taking damage, player characters mark mettle boxes. The hit locations are head, body, abdomen, arms, and legs. Each location has two points of mettle except the head, which has one point. Additionally, player characters have a number of floating mettle points equal to the constitution modifier. These points can absorb damage to any hit location.

Defending

Currently, Hexagram uses active defending—blocking or dodging—sort of like this, rather than resolving monster attack rolls versus player character armor class. The details of the monster attack step are less central to the mettle and trauma system, and any method to decide if an opponent hits a player character in combat should slot in fine here. Even just leveraging the saving throw system seems like it would be a totally functional system for determining whether a character risks taking some damage, bringing armor, mettle, and so forth into play.

Armor

Player characters can equip pieces of armor to any hit location. Armor is ablative, meaning that it reduces incoming damage. The protection offered by a piece of armor maps roughly to the traditional light, medium, heavy (or leather, chain, plate) scale with light armor offering 1 point of protection, medium offering 2 points, and heavy offering 3. Since player characters have five hit location slots, they can mix and match, for example by wearing a heavy visored helmet but a light, boiled leather breastplate. Equipped armor still takes a gear slot, so piling on protection comes at the cost of lower versatility. Additionally, player characters act at a disadvantage when wearing armor with protection higher than the strength bonus.

Damage

When a player character takes damage, determine hit location randomly, subtract armor protection from damage taken (minimum zero), and then mark off one mettle slot for each point of damage remaining. I assume that the magnitude of damage is generally around 1d6 (following OD&D flat damage). If at any point a player character takes damage and has no remaining relevant mettle, then the character is in danger and must roll for peril. This is the step that can potentially lead to serious consequences, including character death.

Hit location (1d6): 1 head, 2 legs, 3 arms, 4 abdomen, 5-6 body

Peril (1d6): 1 messy death, 2-3 bleeding, 4-5 fracture, 6 sprain

Fractures disable the affected hit location. For example, a character with a fractured arm can no longer effectively wield a weapon using that arm. Healing fractures requires magic or taking a haven turn to recover (which would require retreating from a dungeon to town). Sprains work similarly but player characters can recover from a sprain by resting for a single dungeon turn (so, in effect, sprains only influence the current combat).

Other than being messy, gaining the first bleeding condition has no direct result. However, getting the bleeding result again, even to another hit location, means the character bleeds out and dies.

Trauma

Injuries are tricky to handle well in tabletop RPGs. On the one hand, they can make characters much less fun to play even for players on board with working out the implications of player character hardship. On the other hand, a fictional consequence is almost always more engaging than simple HP attrition through both adding narrative color—fan of blood—and changing the context as appropriate—a tiled floor slippery with blood. Further, while permanently changing settings and characters through play is satisfying, ruining characters is generally not. You can’t lose an arm in Dark Souls, and if you did I imagine the common response would be to restart the game. That would be a hardcore lose condition. For this reason, the peril table includes immediate fictional consequences beyond something like HP loss, such as heavy bleeding or broken bones, but defers the possibility of permanent disfigurement, the control of which falls to players through the grit system, described below.

Grit

Bleeding and fractures count as trauma, and surviving trauma strengthens tough characters. Player characters that survive a trauma can mark a grit box during recovery in a haven. Characters have a number of grit boxes equal to the constitution modifier. When a player marks a grit box, they should note how the trauma has permanently marked the character. This could be a scar or something else, and is entirely up to the player, but should be fictionally appropriate to the particular trauma (this would be a good place to insert fantasy prosthetics if such are setting-appropriate, such as necromantic grafts or enchanted wooden limbs). In effect, grit slots are like unlockable extra mettle slots.

False Machine has some creative ideas for scars here.


Implications

This system feels mechanically quite perilous. A mettle slot is roughly equivalent to one hit point, meaning that on average marking 1d6 mettle slots (expected value: 3.5) results in peril for all hit locations lacking armor. However, five-sixths (83%) of peril results are non-fatal initially. Strictly speaking, a one-shot kill is still possible, but is statistically much less common than the OD&D case of 1d6 damage versus 1d6 HP, and could easily be entirely eliminated if desired (such as by changing the messy death result to unconscious and dying, with final death occurring at the end of combat lacking miraculous intervention). Also, the odds improve dramatically with some armor while still maintaining the threat of real consequences.

In terms of complexity creep, this system requires an extra roll to determine hit location if an opponent hit is successful. So, there is a small increase in complexity, but the overhead seems minimal, which I have confirmed in preliminary play testing. The peril step replaces what I would otherwise run as a saving throw versus death, and that is an uncommon occurrence. Tracking the mettle and hit location slots does require a little help from the character sheet, but that seems manageable (see the character record sheet excerpt above).

Halfway houses

Most traditional resolution procedures are binary. For example:

  • Attack roll: either hit (inflict damage) or miss (often boring)
  • Saving throw: either success (maintain status quo) or failure (disaster)

This approach is simple and works well enough most of the time, especially at low levels where the damage from a single hit can make a big difference and missing can build tension, but can sometimes lead to boring slogs when results are chains of misses and the influence of any single action is low.

An alternative approach is to add an intermediate degree of success incorporating unintended consequences and complications into intermediate results. The Apocalypse World 2d6 +stat roll is one method like this that is easy to use:

  • 10+ = success
  • 7-9 = mixed
  • 1-6 = it gets worse

This works well but does have a few potential downsides. Using 2d6 means limited scope for adjustment, as +1 makes a big difference and each additional bonus makes an even bigger marginal difference. Consider (probabilities are approximate, taken from Anydice):

  • 10+ = success (17%)
  • 7-9 = mixed (41%)
  • 1-6 = it gets worse (42%)

Bonuses translated into effective probabilities are:

  • 2d6+1 yields 28% it gets worse, 44% mixed, 28% success.
  • 2d6+2 yields 17% it gets worse, 41% mixed, 42% success.
  • 2d6+3 yields 8% it gets worse, 34% mixed, 58% success.

While this might seem okay if you like to keep numerical inflation to a minimum anyways, it does, somewhat counterintuitively, make the marginal bonus (the next potential +1) always more influential, in terms of mechanical effectiveness, than the last +1.

2d6 is also incompatible directly with d20 systems.

It is easy enough to create a similar method using 1d20 though, and such yields a uniform distribution, meaning that each marginal +1 has the same impact on resulting probability (+5%).

Here is one approach which has some attractive properties:

  • 19-20 success (10%)
  • 10-18 mixed (45%)
  • 1-9 it gets worse (45%)

Single digits = bad is easy to remember; 19 or higher = extra good is also easy to remember. The outcome ranges could easily interoperate with standard ability or attack bonuses. Bonus increments correspond to 5% probability adjustments, which are easy to reason about.

This differs slightly from the approach taken by the traditional attack roll and similar resolution systems, where the roll, modified by properties of a character such as attack bonus, must attain a threshold determined by some external factor, such as armor class. In contrast, the Apocalypse Word target numbers (and these adapted d20 target numbers) are fixed. If the only modifiers to the roll are character properties such as ability score bonuses or attack bonuses, then this resolution mechanism is essentially solipsistic; the result is unaffected by things external to the character.

This could be an issue if you want success versus a dragon to be less likely than success versus a goblin. Using situational penalties could address this problem, but that way lies the hassle of adding and subtracting a host of potential bonuses or penalties. Used sparingly this works well enough, though it is less than ideal, and anyone that has played Pathfinder or even something like traditional AD&D should be familiar with modifier creep (1d20 + strength bonus + attack bonus + magical weapon bonus – odious magical aura penalty … and so forth). It works mathematically of course, but can be a mess.

Here is another approach, using tiers based on academic letter grades for shorthand:

  • 19-20 = A
  • 16-18 = B
  • 10-15 = C
  • 2-9 = D
  • 1 = F

This adds some complexity at first glance, but also supports slightly more granular outcomes that are also relatively easy to remember, especially 1 = F. The only threshold without an easy to remember association is the transition between C and B results, occurring at 16. Further, now it becomes easy to see how the tiers of this solipsistic resolution system could correspond to properties of a fictional world, if desired, without needing to worry about setting difficulty classes by challenge. For example, results of C hit unarmored opponents, results of B hit lightly armored opponents, and results of A hit heavily armored opponents. More generally, C = easy, B = moderate, and A = hard, assuming easy tasks still represent an uncertain outcome that is potentially consequential either way (otherwise why bother rolling at all?). Or: C = success with setbacks, B = success, and A = extraordinary success.

Ultimately, a graduated outcome like Apocalypse World is probably more interesting than succeed/fail systems (heresy?), so I am tempted to interpreting the roll as follows:

  • 19-20 A = extraordinary success/critical hit/overkill
  • 16-18 B = success
  • 10-15 C = success with complications
  • 2-9 D = it gets worse
  • 1 F = it gets much worse/catastrophe

What about the dragon > goblin issue described above? One could also model this difference through hit point totals and the severity of complications.

This set of outcomes is less sensitive to bonus inflation than 2d6 +stat but would still break with Pathfinder-scale bonuses of +15, so some consideration of bounded accuracy would still be required. Basically, just keep bonuses from growing too large. +10 means that a character would always be at least in the success with complications tier apart from the 5% chance of rolling a natural 1, assuming conventional interpretation of natural 1 results.

1-10-16-19 seems easy enough to remember and has the potential to be universal, applicable to anything that one might normally resolve by rolling a d20. I think I may give this a shot the next time I run something.

Hazard System v0.3

The Hazard System is a gameplay engine for traditional roleplaying games designed to facilitate fictional consequences of player decision-making while minimizing bookkeeping.

Find a full HTML version of v0.3 in this post below the divider.

There is also a PDF version.

Significant changes between v0.2 and v0.3:

  • Hazard die results now follow higher = better principle
  • Generalized hazard die:
    1 setback, 2 fatigue, 3 expiration, 4 locality, 5 percept, 6 advantage
  • Introduces free moves, full moves, and conditions terminology
  • Formatted PDF as two letter-sized pages for ease printing two-sided on one sheet
  • Included brief chronological further reading section for context
  • Included simple default subtables for several kinds of outcomes, such as haven shortages and disasters

The text below the divider is released under a Creative Commons Attribution 3.0 Unported license.

Attribution: Necropraxis Productions Hazard System v0.3 (2017)
http://www.necropraxis.com/hazard-system/


Hazard System (v0.3)

The six-sided hazard die deploys threats, manages resources such as light, and keeps time. It is the engine that drives gameplay forward, ensuring that choices have consequences while minimizing bookkeeping. To take a turn, have a player roll the hazard die and have the referee interpret the results relative to the current turn type. During a turn, each player may take one full action. The general form of the hazard die is:

1 2 3 4 5 6
Setback Fatigue Expiration Locality Percept Advantage

Hazard Die Interpretations

Haven Turn Interpretation

d6 Result Interpretation
1 Setback Encounter (use regional table) or disaster (see below)
2 Fatigue Shortage (1 medicine, 2-3 drought, 4-5 famine, 6 trust)
3 Expiration Clear one or more haven conditions
4 Locality Advance season (or other local change)
5 Percept Foreshadow looming disaster
6 Advantage Full recovery

Wilderness Turn Interpretation

d6 Result Interpretation
1 Setback Encounter (use regional table) or road/bridge out
2 Fatigue Rest and consume rations (1/person) or suffer minor harm (1 HP)
3 Expiration Expire transient wilderness condition
4 Locality Shift weather (or other local change)
5 Percept Spoor or clue regarding next encounter
6 Advantage Free wilderness turn

Dungeon Turn Interpretation

d6 Result Interpretation
1 Setback Encounter (use zone table)
2 Fatigue Rest and consume rations (1/party) or suffer minor harm (1 HP)
3 Expiration Expire transient dungeon conditions (light, spell, etc)
4 Locality Shift dungeon state (or other local change)
5 Percept Spoor or clue regarding next encounter
6 Advantage Free dungeon turn

Combat Turn Interpretation

d6 Result Interpretation
1 Setback Opponents act first or additional encounter (use zone table)
2 Fatigue Suffer minor harm (1 HP) if engaged in melee
3 Expiration Expire transient combat conditions (light, burning, etc)
4 Locality Shift battlefield (or other local change)
5 Percept Spoor or clue regarding next encounter
6 Advantage Free combat turn
  • Some disasters (1d6):
    1 invasion, 2 insurrection, 3 fire, 4 earthquake, 5 flood, 6 falling star
  • Some dungeon localities (1d6):
    1 obstruction, 2-3 seal/open door, 4-5 divert water, 6 expose secret
  • Use common sense: ignore results that do not make fictional sense, but only the first time
  • Keep time abstract: quantifying the details precisely is rarely worth the hassle

Moves and Conditions

Moves represent actions relevant to the current fictional context, such as exploring a trackless stretch of swamp. Conditions represent persistence of a transient state, such as adventurer exhaustion. Conditions can apply to areas, parties, or individuals. Strictness tracking conditions is a matter of style. Tokens can help. The lists of moves and conditions below below are suggestive rather than complete. Improvise others as appropriate, according to referee ruling.

Haven turns represent several days or weeks of rest and recovery.

  • Free haven moves: advance/level up, prepare spells, recover, recruit, resupply
  • Full haven moves: craft gear, scribe scroll, conduct research
  • Haven conditions: curse, famine, pestilence, shortage, siege, winter

Wilderness turns represent travel and making camp, approximately one day and night. Making a wilderness move requires consuming a ration or taking the exhausted condition in addition to rolling the hazard die. If already exhausted, at the start of a wilderness turn suffer minor harm (1 HP). Determine randomly whether setbacks occur during day or night.

  • Free wilderness moves: access known landmark in current area, survey adjacent areas
  • Full wilderness moves: travel to adjacent area, search, explore, hunt, track
  • Wilderness conditions: exhausted, lost

Lost: Travel is no longer an option. Use search to locate a landmark, removing the lost condition on success.

Dungeon turns represent exploration at architectural scale, approximately tens of minutes or a few hours, assuming careful advance into hostile places.

  • Free dungeon moves: look under a rug, open unstuck door, pull lever
  • Full dungeon moves: climb, force a door, move to adjacent area, pick a lock, search
  • Dungeon conditions: candlelight, torchlight, overburdened

Combat turns represent tactical actions occuring over seconds or minutes.

  • Free combat moves: shout command, drop held item,
  • Full combat moves: shoot, spell, strike, throw, withdraw
  • Combat conditions: burning, defended, grappled, prone

Notes and Further Reading

  • Consider using a simple slot-based encumbrance system, such as one item per point of strength.
  • Locality results work best if you design areas with countdowns or aspects that can shift between states.
  • I replace traditional initiative with the combat hazard die.
2012-09-16 http://www.necropraxis.com/2012/09/16/abstracting-missiles/
2013-04-10 http://www.necropraxis.com/2013/04/10/solipsistic-hexes/
2014-02-03 http://www.necropraxis.com/2014/02/03/overloading-the-encounter-die/
2014-05-22 http://www.necropraxis.com/2014/05/22/proceduralism/
2014-12-23 http://www.necropraxis.com/2014/12/23/hazard-system-v0-2/
2015-02-09 http://dungeonofsigns.blogspot.com/2015/02/luceat-lux-vestra-making-light.html
2016-07-22 http://www.necropraxis.com/2016/07/22/tactical-hazard-die/
2016-09-19 http://www.necropraxis.com/2016/09/19/let-it-ride-or-push-your-luck/
2017-06-11 http://www.paperspencils.com/2017/06/11/the-haven-turn/

Released under the Creative Commons Attribution 3.0 Unported license. Typeset using Pandoc and LaTeX.

Attribution: Necropraxis Productions Hazard System v0.3 (2017)
<http://www.necropraxis.com/hazard-system/>