Barbed Darts (BTD6)

"Sub's darts can pop an additional 3 bloons each."

- BTD6 Description

Barbed Darts is the first upgrade of Path 2 for the Monkey Sub in Bloons TD 6. It increases pierce of each main dart from 2 to 5. For Airburst Darts, darts still split on impact but each individual airburst dart receives +3 pierce. For Bloontonium Reactors, pierce of the damaging radiation zone increases from 50 to 70.

It costs $380 on Easy, $450 on Medium, $485 on Hard, and $540 on Impoppable.

Summary
Barbed Darts will produce more pierce potential overall compared to adding Twin Guns, but for the same cost it doesn't have as much early-game value in comparison. This is because a majority of the issues in early-game come from the faster bloons rather than grouped bloons. However, this upgrade can come in handy when extra dart pierce is necessary.

Tips

 * This upgrade increases pierce, allowing for better popping power. It's usually just a stepping stone to higher upgrades.
 * There are some uses out of the 0-1-2 for advancing against grouped rounds. However, in general cases, grouped bloons aren't always a problem and 2-0-2 is better for general cases.

Trivia

 * Barbed Darts currently costs the same as the Twin Guns upgrade.