Most of the systems played at UK Armageddon are indoor only systems.  The main focus of Armageddon has always been the indoor systems and will continue to be so.  It is generally felt that indoor systems offer a much greater level of uniqueness compared to each other, while most outdoor systems play in a very similar way.

Outdoor systems have been used on a number of occasions from a variety of manufacturers.  The format used has changed each year when outdoor has been used based upon field operator recommendations.

As a result there is no official format used for UK Armageddon, and Outdoor is generally not regarded a core system.

As no standard format exists the following are formats previously used:

• Elimination - Where players are eliminated from the game.  The team with the most players left at the end of the allocated time are the winners.
• Frags - Where players can respawn in to the game when shot out.  The team with fewest respawns wins.
• Capture the Flag / Shield / Object - Where a team has to capture an object from the other team, generally while defending their own.
• Domination - Where a special unit is used that each team can shoot to gain control.  The team who control the box the longest during the game win.
• Timed Objective - Where an objective is set, and each team takes turns at it.  Whichever team manages it in the shortest amount of time wins.

Outdoor rules tend to vary somewhat but these rules are followed at UK Armageddon:

• No covering of sensors.  This includes using any part of your body or gun to shield a sensor from your opponent.  Examples include placing hands over sensors, or bending over and looking between your legs.
• Dead Men Don't Talk - Once shot out of lives you must not speak, point or communicate in any way to your team.  This includes calling out that you are dead.
• Dead Exit - You must leave the game once killed out returning to your appropriate start point.  You must not remain in your position