Toughness

There are people who work with you in missions who offer you assistance. The main people will be Clay Simons, Terry Thorpe and Jim Fitzgerald who are either extremely hard to kill or can't die. But there are other people including these people who every time you kill an enemy gang, they will get tougher and be more effective in combat. They will gain weapons skill and health. If one of your gang falls, they will be replaced.