A Gaming Contract is a sort of manifesto or agreement everyone in a game group adheres to. It documents table rules, off limit topics (romance, sex, etc.), pvp stance, acceptable behavior, use of devices, types of dice or devices, parameters for character creation, food and drinking at the table, vtt use, etc. For a GM, it has your expectations and what players can expect of you.
What are the limits on sensitive subjects? Realize this IS roleplaying and a game. The realities of more brutal milieus may be unsettling, but that’s part of the challenge. How far can people expect the descriptions to go. What about romance, sex, PvP, etc.
Determination of Intent: The GM’s determination of a characters/players intent will stand unless it was specifically spelled out by a player, so long as the GM can explain it within the context of the characters code(s) or outlook. Its not the GM’s job to second guess the players.
End of Character Turn: After a character has ended their turn and the next character’s (PC or NPC) has begun to resolve there is no going back and applying effects or changing outcomes.
Track Character Supplies: As your character uses equipment and resources, be fair and mark off what is used. Just as you do not have a endless free supply of items, neither does your character. This includes mundane supplies and special ones (magical, etc.) If the GM catches an abuse of this, they are free to impose penalties such as automatic failures or equipment breakage.
Players are responsible for creating their own characters using the rules DnD 5th edition, filtered by the general Incarna limits and adjustments. NOTE: “My character would do that” is no excuse for creating unwanted chaos inside the PC party, or for dragging the party into volatile situations unwanted. Comedic effect is one thing, forcing the party into fights and confrontations that threaten to get them killed repeatedly is unacceptable.
Character Review: The GM will approve them outside of game time, before they get used in game. The GM will disallow or may penalize obvious min/maxing and attempts at taking minor disadvantages to get a few more perks. Negative traits creating unfair vulnerabilities for the entire group and will be painfully exploited by the GM.