Round 3

Round 3 is a round in Bloons Tower Defense where Blue Bloons make their first appearance; this is true for every Bloons TD game except BATTD (which introduces them on round 2).

In Bloons TD 6, this round is the round that all Hard Mode gamemodes (with the exception of Impoppable & CHIMPS) start on.

Description
In BTD6, this round is characterised by a stream of Red Bloons interrupted by a few Blue Bloons partway through.