One of the more interesting things in the Warhammer RPG is that magic can be rather unpredictable, making it very interesting.
Here's a simple attempt at "crits and fumbles" for magic in OSR games. Comment away if you think its great or stupid.
Whenever a spell is cast, roll a D6. A roll of 2-5 indicates everything works as expected (or not, depending on saving throws).
A roll of 1 means something unfortunate occurred. Roll below:
1: The spell simply fizzles, and is lost
2: Randomly determine another spell in memory that is cast instead at the original target
3: The spell strikes the wrong target (helpful spell targets an enemy f.x.)
4: The spell has the opposite effect (a fireball heals, while invisibility draws attention to you)
5: Spell works but the caster takes 1D6 damage.
6: Spell works but the caster loses a random other spell from memory as well
A roll of 6 means something excellent has happen. Roll below:
1: Any saving throws are at -2
2: Durations and areas of effect are increased by 50%
3: Spell remains in memory
4: Magical energies heal the caster 1D6 hit points
5: Spell is cast super quick, and the caster may still take another, non casting action this round.
6: Spell is permanent! A fireball might create a permanent ball of flame, while an enchantment never goes away
What's your take on magic and reliability? Both as a player and as a DM? Leave a comment.