In most of the campaigns I’ve played in, the PCs wind up forming a loosely-organized organization, regardless of how they come together. Sometimes the PCs are part of a broader organization like The Harpers or Knights of Solamnia, but generally they exist as their own company with a creative name like: 5 Adventurers for Hire, Dewey Killem and Howe, or The Travelling Killburys.
In some of my campaigns we’ve taken the “Party Group” pretty seriously, with the characters drawing up formalized business documents, appointed officers, and had written policies for hiring NPCs. Once or twice another player went to the effort of drafting up a paper charter. That prop was pretty awesome and well appreciated by everyone else at table; I wish I still had it to show you. I’m not suggesting that every group needs a formal corporation, but it is a nice way of bringing the individual characters together into a group that exists for a larger purpose.
In-game, the kind of company will depend on the players personalities. If the group is a bunch of chaotic mercenaries, there may be no agreement beyond mutual distrust and profit. Other characters may be fine with a handshake (a gentleorc’s agreement, if you will) to seal the group together. Particularly lawful characters may want a charter so the roles and rules are well defined, and mistrusting types might also want some kind of formal arrangement. In a party with one sociopath and four do-goody’s, a formal contract is a great way for that one jerk to fleece his compatriots.
Depending on how authentic you want to be, you can have the DM register your character with whatever governmental organization keeps track of those things. This formal organization might get the players guild memberships, voting rights, land ownership, protection from legal actions, but also might make them susceptible to tithes or taxes. NPCs may be willing to work for or help out a more legitimate enterprise than “some dirty dudes with swords”, unless that is the party name.
Out-of-game I don’t recommend drawing up an actual contract between players, but go ahead and have one as a prop to represent the one the characters agreed to. It’s something to keep in a file along with the treasure ledger and party photo.
Here’s a sample contract that I made sound as legalish as I could, based upon what I learned from bad sci-fi, law & order, and my rental agreement. Let me know what you think, and feel free to modify or use it for purposes.
We, the undersigned, do hereby agree to form the Corporation _________________ for the purposes of Adventuring. We agree to kill any form of bad guys and collect their belongings for the furtherance of adventuring activities. We agree to equally divide all treasure based on gold piece value among the undersigned. Other entities acting on the behalf of The Corporation, will be paid a wage summarily based upon their abilities, level, risk, and suggested value in the guidebooks.
Article 1. The aforementioned heirlings shall not get an equal cut of the treasure unless agreed to upon by all members of the undersigned. The party treasurer, as agreed to by unanimous vote, can disburse up to 15% of the party funds at his/her own discretion to pay for healing potions, inn services, bribe guards, or other sundries as needed for the purposes of Adventuring.
Article 2. The acceptance of any Quest requires a unanimous vote among all present party members. In addition, the group cannot consider any morally objectionable Quest unless it is the least objectionable of all options. No entity, material or planar, can usurp the current Quest without a unanimous vote of the board members.
Article 3. No backstabbing. All treasures found must be disclosed and shared with the group, but the individual finder may claim “dibs.” If one member of The Corporation does harm against another, the injured may seek redress in the form of financial compensation by the injurer by appealing the uninvolved member(s) of the party. In the case of insufficient knowledge or members to pass judgment, the injured party may appeal to a Lawful diety or high-level sage.
Article 4. The Corporation exists to provide a cohesive team for going on Adventures, and may not be used by legal authorities to incriminate the remaining members for one asshole’s behavior.