Talk:SAS: Zombie Assault 4/@comment-75.172.187.96-20141129105432/@comment-24659969-20141130151030

Two reasons:

1. out of ammo

2. You put too many turrets. Player can only keep two of their last put turrets active or three with mastery (not available on Mobile atm)

This is to prevent turret spamming. Which could cause the game way too easy where players could drop all their turrets and go afk. There also few technical reasons like lags caused by multiple turrets firing at the same time.