In the setting I’m running, magic is produced by draining energy from nearby living beings, meaning the fewer life-forces are in an area, the higher the chances are for a caster to drain a considerable amount of life from themself and to cause a mishap. So mishaps are triggered on low extraordinary attribute rolls and here are the chances:
moderately populated area: Severe Mishap on rolls from 1 to 5 / Light Mishap on rolls from 6 to 10
sparsely populated area: Severe Mishap on rolls from 1 to 10 / Light Mishap on rolls from 11 to 15
Obviously additional areas could easily be defined for example by moving the chances for mishaps to happen up, or by removing the chance for severe mishaps to happen completely.
There are two different tables, one for light mishaps and one for severe mishaps, which any magic user has to roll on once the result of the extraordinary attribute roll has been determined and falls in one of these ranges.
Light Mishap Table
- Light Damage (1d4)
- Moderate Damage (1d6)
- Inflicted with Demoralised PL3
- Inflicted with Disarmed PL
- Inflicted with Forced Move PL2
- Inflicted with Immobile PL1
- Inflicted with Knockdown PL1
- Inflicted with Persistent Damage PL2
- Inflicted with Silenced PL2
- Inflicted with Slowed PL1
- Affected by Darkness PL2 for 1 turn
- Mystery Box
Severe Mishap Table
- Damage (2d6)
- Lethal Damage (1d4)
- Full duration Demoralised PL3
- Full duration Persistent Damage PL2
- Full duration Silenced PL2
- Full duration Slowed PL1
- Inflicted with Blinded PL5
- Inflicted with Deafened PL5
- Inflicted with Sickened PL5
- Inflicted with Stunned PL5
- Mystery Box
Note that both tables contain an effect called Mystery Box, which is essentially meant to be a placeholder for narrative consequences that depend on the situation, for effects with which the GM can get creative and which are hard to pin down in a standardised table.
I could see this system also being used for other settings, which involve drawbacks for magic users, like the classical fantasy trope of Wild Magic, without too much tinkering or adapting being needed.
So I hope you guys enjoy the premise!