Storyline Rebels: Source is a multiplayer mod for Half-Life 2. You and your teammates play as the rebels defending against relentless assaults from the combine in round based gameplay. Can you hold out against the combine assaults long enough? You can't do it alone. Gameplay All players are on the same team, facing off against NPC combine. There are 2 gamemodes: Survival: You have to hold out until the round timer hits 0. Capture the Flag: Can you capture all of the flags or defend the flags until the round ends? Although, maps can follow many different styles than the gamemodes presented above. For example, a map could be similar to a progressive single player map, or you have to ambush a squad of combine. It's really up to the mapper. What about some King of the Hill against NPCs? Rebels: Source is about having fun with your friends, using teamwork with your friends and blowing some combine away too.