No god-modding: There is no way that your character is invincible with limitless powers who could kill the others with a single look, nor could a 12-year-old child defeat a knowledgeable adult, say like, a teacher. Apparate into and out of the IAM is also forbidden.
No power-playing: You can't operate other users' character without their permission in a roleplay, which is, in other words, you can't decide the fate or decision of a character that's not yours.
No meta-gaming: Your character can't know everything happening around. Do not apply any information retrieved from OOC on your characters.
Do not mix "In Character" (IC) with "Out of Character (OOC): Do not mix things happened IC with OOC. No meta-gaming is one. Also, do not take offense for what is said in roleplay, especially when roleplaying with a user who is using a mean character. IC and OOC should be separated.
Extreme violence is prohibited: It is acceptable that your character gets into a fight with another, but keep it PG-13 or lower.
Romantic relationships: It is also perfectly fine for your character to have romantic relationship with other user', but also do keep it PG-13 or lower.