Most contracts will be dealt with simply by handing a contract to the chosen Merc. but if the contract is level three or higher this will need more then one Merc. This is where the briefing room comes in. A major contract will need multiple Mercs. as I have said, but since only one contract will ever be made, for privacy and legality reasons it will be told by either Camaxtli or Gaia too the chosen Mercs.