Much like with weapons, there are some common aspects of spells that can be factored out into properties. In so doing, we can make spell descriptions more concise, and also create other game relationships, such as the oppositional nature of ice and fire spells, or light and shadow spells (I plan on making these oppositional natures part of a basic counter-spell system, in addition to being useful for damaging enemies with certain vulnerabilities).
Some of these properties reference aspects of the abstract tactical positioning system (such as the area property), which will be more fully explained in a separate post.
Spell Properties
Acid
Inflicts acid damage. Save or cause permanent disfigurement, to either sufaces or creatures. Weakens a breakable object subject to acid (such as a door with metal hinges); +2 to future force checks against affected objects.
Allies
Effects all allies that could be reached by a ranged effect.
Area
Affects all creatures in one skirmish melee (the size of a large room). Does not distinguish friendlies from enemies.
Chain
For each hit, allows another target to be selected within the same melee (which requires a further spell check). Think chain lightning, arcing between multiple targets. The first miss terminates the effect.
Damage-N
Inflicts N +INT damage on hit.
Fire
Inflicts fire damage. Flammable objects, such as flasks of oil or bombs, must save or ignite.
Half
Spell still inflicts half damage (or half effect, which should be clear contextually) on a miss.
Ice
Inflicts cold damage. Liquids affected must save or freeze. On successful save, targets still take a -1 physical penalty to actions on their next turn due to the slowing. May be used to create treacherous ice in combination with water.
Interrupt
May be cast out of turn. No more than one interrupt spell can be cast per round by a given spell caster.
Lightning
Inflicts lightning damage. May also be useful to power strange devices or mechanical creatures. Becomes a weak area effect (1d6 area) in a submerged environment.
Poison
Inflicts poison damage.
Psychic
Only works against creatures with a mind or consciousness. If the spell inflicts damage, the damage is psychic, and has no physical manifestation. Generates aura that can be perceived by psychically attuned creatures. On a miss, psychic targets may take a free counterattack as an interrupt. Targets with animal intelligence or lower take half damage on a hit and no damage on a miss if the spell also has the half property.
Ranged
Equivalent in range to a missile weapon. Requires line of sight.
Self
May only affect the caster.
Shadow
The antithesis of light.
Sustain
Spell effect may be sustained indefinitely after the initial mana cast is paid, as long as the caster remains conscious and does not cast another spell with the sustain property.
Touch
Requires touching the target (this is an unarmed melee attack if the target is unwilling).