Overdrive is the fourth-tier Path 3 upgrade for the Tack Shooter in Bloons TD 6. It allows the Tack Shooter to attack twice as fast as Tack Sprayer and pop two bloons per tack instead of one. This makes them good low-cost choices for popping grouped bloons against tight corners. It costs $2,125 on Easy, $2,500 on Medium, $2,700 on Hard, and $3,000 on Impoppable.
It turns the body of the Tack Shooter into a very dark gray color, along with making the tack icon on top of the Tack Shooter red. It adds a base, making the Tack Shooter taller. When Path 1 upgrades are bought, the red tack icon features additional tacks. When Path 2 upgrades are bought, Long Range Tacks flattens the top of the Tack Shooter, while Super Range Tacks mounts the Tack Shooter with an taller base.