Want to run a fantasy-based game with Stars Without Number? Most of the time, it’s simplicity itself. Just have the players pick setting-appropriate backgrounds, remix a few training packages, and use the equipment and monster lists from your favorite retroclone. But what about magic? The Psychic class can cover a lot of magical terrain, but there are many settings that involve very different types of sorcery that require their own systems. The simplest way to handle this involves grabbing your favorite retroclone and peeling the Cleric and Magic-User classes out of it.
Clerics: Give them an Expert’s attack bonus, saving throws, and hit dice. Their class skills are the same as a Psychic, and for a training package they can pick up to four skills, up to two of which can be non-class skills. They gain two additional skill points each level. They Turn Undead and use spells in the same way as given in the retroclone being used. They can use any armor, shields, and any blunt weapon.
Magic-Users: Give them a Psychic’s attack bonus, saving throws, and hit dice. Their class skills are the same as an Expert’s, and for a training package they can pick up to four skills, one of which can be a non-class skill. They gain three additional skill points each level. They can use spells in the same way as given in the retroclone being used. They cannot wear armor or shields, and can use only those weapons given for magic-users in the source retroclone.
But what’s this? You want a different flavor of magic-user? One with an ability to cast magic that hinges on physical strain and the ability to channel awful eldritch powers? Try these variant Mage rules on for size, then.
Mage: Mages are in all ways equivalent to the Magic-User class described above save in the way in which they prepare and cast their spells. At the beginning of the game, the player and the GM take turns picking eight spells from the combined first level spell lists of clerics and magic-users, each choosing those spells that best fit the Mage’s education and style of magic. These choices form the spell list for the Mage. New spells can only be added through research, or the discovery of some arcana utterly appropriate to the Mage’s style as determined by the GM. As the Mage acquires access to new spell levels, this process is repeated to form the list for that level. Mages can start with the knowledge of any two first level spells on their list. Further knowledge must be acquired from a teacher who knows the spell or a scroll inscribed with the enchantment.
Mages must prepare their chosen spells each morning, performing the necessary propitiary rites, meditations, and study in order to fix the spells in their mind. A mage can prepare as many spells of each level as is allowed by the spell progression table for the retroclone being used, plus the Mage’s Intelligence modifier. A first level mage with an Intelligence of 14 could prepare two first level spells, for example, while a 5th level mage could prepare four first, three second, and two third level spells.
Once a spell has been prepared, a mage can cast it at will. A prepared spell is not consumed in the casting. Instead, after each casting, the Mage must make a Mental Effort saving throw at a penalty equal to the spell’s level and a bonus equal to their character level. If the save is failed, the Mage earns one System Strain point and becomes Fatigued. A Mage that is already Fatigued falls unconscious for 1d4 rounds after failing a strain save, awakening Fatigued at the end of it. A Mage with maximized System Strain cannot cast any further spells. A half hour of rest eliminates Fatigue, but Fatigue cannot be banished by magic.
A Mage that prefers not to risk accruing System Strain may omit the save and buffer the enchantment with his own vitality, automatically becoming Fatigued but avoiding the expenditure of a System Strain point. Conversely, a mage may choose to “overcharge” a spell, hurling more energy into it that he can safely channel. For each additional point of System Strain spent in boosting the spell, it does +1 damage per die of effect and range and area of effect is calculated as if the caster’s level was +1 higher. Any number of available System Strain points may be spent on overcharging a spell, but the Mage automatically takes an unavoidable 1d4 damage for each point spent, with a Physical Effect save for half.