Group agrees no PvP during Session 0, and the characters are doing party loot. What level of "rogue steals loot" starts to impinge on that? Any stealing at all? Taking treasure the party (likely) wouldn't get? Taking loot from creatures the party defeats? Pickpocketing the party? It's all okay because PvP is explicitly combat?
This really is hypothetical, no need for advice on how to work it out.
From my house rules documentation:
Having A Thief In The Party
NOTE: Being a thief doesn't give you special rights to steal treasure that would otherwise become group property. In other words, just because your character CAN steal things from treasure chests that he opens while other PC's aren't looking, doesn't mean he has special permission to do so. It certainly doesn't mean you get to have your actions kept private or secret from either players or PC's any more than the PC's in another room will have their actions kept private and secret from the other players and PC's until such time as they inform other party members what they were doing.
Other players and their PC's have every right and every justification in expecting that as PC's adventure together that everyone shares in ALL treasure. Stealing from fellow party members in that way basically makes you
or your PC a jerk for no other reason than you CAN be. I don't much hold with that.
If you want your character to effectively steal from your fellow PC's then you ought to have SOLID roleplaying motivation to do so beyond, “I feel like it,” or, “The opportunity came up and I took it.” The reason for that is when other players and PC's discover this kind of behavior then as a rule it disrupts the game. It annoys players. It annoys PC's. It derails the ongoing flow of the game while this side-issue is then dealt with. And most especially, it virtually never ends well for anyone when it comes up. There are bad feelings both among characters and players.
For this reason, such behavior is directly discouraged. Not
forbidden, but I personally won't permit casual theft within the party without making the perfectly understandable assumption that this is a roleplaying road you have chosen quite deliberately. If you do it, be warned: You are taking very, VERY deliberate action. I will not conceal it during regular play. Trying to get around it by passing notes to me won't be allowed. Other
players at the table will know at the very least. If you DO have reasonable motivations then it had best be good enough to convince ME to permit it and for other players to not be sufficiently upset about it to make a stink. Only then will I enable you to perhaps just keep it secret from other players.
Even so, I will not stand in the way of other players or their characters discovering what's happening. That's YOUR problem as a player. If you do this then YOU had best be prepared to dazzle with your roleplaying skills and smooth the otherwise justifiably ruffled feathers of players. My only role in it as DM will be to keep it from being disruptive to the game. If everyone is still having fun AND keeping it in-character then we're all cool. But you WILL be thrown under the bus with the first sign of it being a problem. DO NOT DO THIS LIGHTLY because the game in general will not be sacrificed to keep YOU satisfied with this action.
I've repeated elsewhere – nobody has a right to be a jerk in this game. Nobody gets to use, “I'm just playing my class,” or, “I'm just being true to my character,” as ANY kind of excuse for being an ass. Thief PC's have no inherent right nor special privilege to help themselves to extra treasure at the expense of the other PC's just because they often have greater opportunity to do so. The fact that the other PC's are accepting of a thief class PC in the party does not mean that, “they get what they deserve/ask for,” or, “they should have expected it,” as far as losing treasure to a PC thief.
Analogy: Stealing someone's french fries at lunch is not a crime. Often it can be funny. But sometimes it ISN'T funny – like when that person is hungry and wanted to eat their own fries. Then it IS a problem. It becomes YOUR problem – a problem which YOU created. I have no obligation to help you out of that jam except what's necessary to end the disagreement and get the game back on a smooth course. Exile of the thief PC which would require the player to roll up a new character is probably the best outcome a player would then have any right to expect. Harsher, in-game response by PC's is certainly possible. Don't put yourself in that position.
Don't put other players in that undesirable position. Most of all – don't disrupt the game doing this when you have been given a vigorous, emphatic warning not to do so.
