I had a PC who, during the creation of her character, wanted something to happen every time her character became stressed or very upset. Since she was running a Sorc, I decided to run with that and compiled a list of 20 things that could happen when her character became stress/upset. It became very amusing when one misfired spell would lead to more stress, which would lead to another misfired spell.
01-one item out of every party member’s possession is rotated
02-a random player speaks a foreign language
03-one item from each of the party members’ possession ends up in the character’s possession
04-All hair withing 30 feet turns bright pink
05-for 1d6 days, a random character’s gender changes. Can be undone prematurely by dispell magic
06-character looses an item for 1d4 minutes
07-character finds 1d4 gold, 1d6 silver, and 1d12 copper on her person
08-some of the party’s gold ends up in another character’s possession
09-100 tiny newts appear where the caster was pointing
10-character uncontrollably speaks his/her thoughts aloud
11-anything the character touches turns into gold as the spell
12-roll a d6. A random character smells of 01-rotten eggs, 02-fine smelling cologne or perfume as appropriate, 03-burning silly string, 04-strongly of skunk, 05-fresh rain, 06-lilac
13-the hair color of someone nearby changes. Roll a d6 to determine color: 01-red,02-blonde,03-black,04-brown,05white/grey,06-pink. If color rolled does not change the hair – reroll
14-a random person is teleported to a random (nearby, but slightly inconvenient) location
15-a random person’s steps make duck-quacking sounds. Lasts for 2d6 minutes. there is a minus 5 to any hide or move silently checks during the duration of the spell-effect
16-character becomes one size larger for 10 minutes
17-character becomes one size smaller for 10 minutes
18-Target is cloned for the next 1d4 minutes
19-person is under the effects of reverse gravity.
20-a random player gains half their weight in fat for 1d6x10 minutes
Unless otherwise stated, random player is decided by rolling a d6. 01 is always the misfiring spellcaster. 02-05 are the other PCs. 06 decides the misfired spell affects everyone – the spellcaster and PC alike.