Zombie Dice and Spell Interruption

[The following rule utilizes the Zombie dice from Zombie Dice, a game published by Steve Jackson Games. Zombie dice, which will hereafter be referred to as dZ, have the following faces: brain, footprints, and shotgun blast (abbreviated here as simply blast). The distribution of faces varies by color. A green dZ has 3 brains, 2 footprints, and 1 blast. A yellow dZ has 2 brains, 2 footprints, and 2 blasts. A red dZ has 1 brain, 2 footprints, and 3 blasts.*]

When a spellcaster announces an intention to cast a spell and the casting is interrupted, the spell is disrupted and lost. It neither takes effect, nor can it be cast again until it is re-memorized. If, however, the caster decides to attempt to maintain concentration in spite of the interruption, there is a chance that the spell may still be successfully cast, but there is a chance for a mishap. The caster must roll 1dZ depending on the nature of the interruption. If the distraction is minor (the caster is jostled, asked questions, or briefly loses sight of a target), the caster must roll a green dZ. If the distraction is major and physical (the caster is physically injured or threatened with injury), the caster must roll a yellow dZ. If the distraction is major and mental (the caster is magically or psionically attacked) or the caster fails a saving throw, the caster must roll a red dZ. The result of the roll is compared to the table below:

dZ	Effect
brain	The spell is cast successfully.
footprints	The spell is disrupted and lost.
blast	Roll on the Spell Mishap table.

Spell Mishap

Roll 1d6

1. Stunning Blow. The spell fails and the caster is stunned for 2d12 rounds.
2. Reversal. The reverse of the spell is cast. If there is no reverse version, it backfires instead.
3. Backfire. If offensive, it affects the caster. If beneficial, it affects the opponent. If neither apply, then the result is concussion.
4. Concussion. The spell fails and the caster is rendered unconscious for 2d12 hours.
5. Memory Drain. The spell succeeds, but all memorized spells are forgotten in the effort to maintain concentration.
6. Explosion. The spell fails and the uncontrolled magical energy explodes causing 1d6 hit points of damage per level of the spell to all within a 10' radius.

* Standard six-sided dice may be substituted as follows:
"Green" d6: 1-3 = brain, 4-5 = footprints, 6 = blast.
"Yellow" d6: 1-2 = brain, 3-4 = footprints, 5-6 = blast.
"Red" d6: 1 = brain, 2-3 = footprints, 4-6 = blast.