||Shoots faster than normal.
- For the BTD4-5 counterpart, see Rapid Fire (BTD4-5).
- For the Mortar Tower upgrade, see Rapid Reload.
- For the Dartling Gun upgrade, see Faster Barrel Spin.
Rapid Fire is an upgrade for the Monkey Ace in BTD6. It increases attack speed of all attacks by 67%, except for Spectre and Flying Fortress, which attack 33% faster with the upgrade.
It costs $550 on Easy, $650 on Medium, $700 on Hard, $780 on Impoppable.
- Despite being the 3rd upgrade in BTD4, it became the first upgrade in each path in BTD5 and BTD6.