I have already discussed this on Google Plus, but I figure I should put it in a post for officialness (and stable accessibility). These rules are somewhat similar to the spell training rules for the recent sorcerer class, but in this case are intended to apply to standard magic-users.
In the upcoming S&W Complete based Finchbox campaign, sorcerous classes (magic-users, elementalists, necromancers, vivimancers) will begin with three first level spells and learn one per level gained as described below. The same procedure will apply to
clerics demon hunters (which will use the LotFP cleric spells), but with only one spell to begin with at first level.
See also Alex S.’s related comments.
Characters may only learn spells when a new spell slot is gained. For odd levels (including first), this spell is determined randomly. For even levels, spells may be selected by the player from the appropriate spell list. One new spell slot is gained per character level, with spell level equal to character level divided by two, rounded up. This means that spells will be acquired by magic-users as follows: 1st, 1st, 2nd, 2nd, 3rd, 3rd, and so forth.
Spells may not be copied from spell books or scrolls. There is no need for players to decide which spells to prepare, as each spell known may be cast once per session.
Read magic is a class ability rather than a spell, and requires a successful intelligence check (only one try per magical text is allowed per character). Magic-users can cast spells that they do not know using scrolls, talismans, and fetishes. Such items cannot be created and must be found by adventuring (or, occasionally, purchased from curiosity shops or wandering cheapjacks).