Alternate Bloons Rounds

"You know 'alternate' just means harder right?"

- Round 5 Pre-Round Comment

Alternate Bloon Rounds (also shortened as ABR) is a mode in BTD6. Players start on Round 3 and must beat Round 80, like Hard Mode. However, all rounds up to 100 are modified, stronger types of Bloons appear earlier, making it more challenging. For example, Camo Bloons appear on Round 5 as opposed to Round 24. Certain rounds get the Fortified property or have intentionally low RBE, to increase the overall difficulty.

Many of the rounds in Alternate Bloons Rounds feature waves of bloons that are substantially different to their corresponding non-ABR rounds. Most of the earlier rounds are mostly different, while later rounds typically modify their pre-existing round format. An example of this is ABR Round 63 using dense waves of Ceramics, Camo Ceramics, and MOABs, instead of just Ceramics in the normal Round 63. Other notable examples of modified standard rounds include Rounds 11, 20, 24, 25, 27, 28, 30, 31, 33, 34, 40, 42, 46, 49, 60, 78, 79, 80, 83, 85, 87, 90, 93, 95  99, and 100.

Rounds
*Note: Rounds 1 and 2 do exist in the code, but never appear in normal Alternate Bloons gameplay. Round 1 has 10 very spaced Blue Bloons, while Round 2 is almost identical to the normal rounds. These rounds can be seen in certain challenges (including Odysseys).

First instances of types of bloons are in bold.

''This section is incomplete. Help by finishing off the missing rounds.''

*These rounds do not normally appear in standard play although in custom challenges they may appear

**Following the Version 25.0 addition of predetermined Rounds 101-120, this has affected all games except ABR, which still uses the old rounds system.

Trivia

 * In this mode, the MOAB is the only MOAB-Class Bloon whose non-Fortified form appears more than one round later than its Fortified form.
 * Fortified BAD appears in ABR Round 100 replacing normal BAD; that appears at the end of ABR Round 99 instead.
 * This is one of the only ways the Fortified BAD appears, the other being Rounds 140 or 200.
 * The Alternate Bloon Rounds rules only continue to Round 100 and after that, standard freeplay rules and ramping applies.
 * On Round 5, a Camo Regrowth Red bloon appears as the last bloon of the round. This is a reference to a meme in the BTD6 Community where it is seen as a bloon that is extremely difficult to pop.
 * The Z.O.M.G. and D.D.T. are the only MOAB-Class Bloons that do not appear as a fortified variant on their standard debut round, rather having 2 highly spaced Z.O.M.Gs or 4 D.D.Ts
 * The icon for Alternate Bloons Rounds is identical to the icon for Freeplay Mode when it appears after winning any game.