Where a red turret is the first to fire:
+ = Laser Rockets
+ = Tazer Rockets
+ + = Poison Gas Rockets
+ + = Nuke
+ + + = Napalm Rocket
Where a green turret is the first to fire:
+ + = BFG
+ + + = Rocket BFG
Where a blue turret is the first to fire:
+ = Land Mine
+ = Cluster bomb
+ + = Sparky Cluster bomb
+ + = Big Landmine
+ + = Sparky Landmine
+ + = Big Cluster Bomb
+ + = Laser Cluster Bomb
+ + + = Big Laser Cluster Bomb
+ + + = Big Cluster Bomb Landmine
+ + + + = Big Laser Cluster Bomb Landmine
Where a yellow turret is the first to fire:
+ + = Tazer BFG
+ + + = Black Hole
+ + + = Shockwave