Bonus Tower

A Bonus Tower is a feature seen in Bloons Monkey City Mobile and Bloons TD Battles Mobile. It varies depending on game.

Bloons Monkey City Mobile
In Bloons Monkey City Mobile, a Bonus Tower is one free tower to use in a single game. It gives a random free tower to use for the one game. Once a random tower is selected, the Bonus Tower cannot be carried over to other games.

Bloons TD Battles Mobile
In Bloons TD Battles Mobile, a Bonus Tower is an extra slot for any random tower, even if the tower isn't fully unlocked yet. It costs 1 to get a Bonus Tower, and it costs 3 to re-roll the Bonus Tower.