Co-op

Co-op lets two to four players defend the same map together, with every game mode and every map available. It unlocks at player level 20. Each player builds in their own part of the map, the team shares one pool of lives, and the game splits cash and hero XP across the team. Here is how lobbies, territories and money work, and how to stop a random lobby from leaking round 63.

How to start a Co-op game

There are two ways in:

• Quick Match: join a public game with random players. You pick a match type. Any Game can be any map, difficulty and mode. Medium Game uses Beginner, Intermediate or Advanced maps on Easy, Medium or Hard with Standard, Primary Only, Military Only, Reverse, Magic Monkeys Only or Double HP MOABs. Long Game uses Intermediate or Advanced maps on Hard with Standard, Magic Monkeys Only, Double HP MOABs, ABR, Impoppable or CHIMPS.
• Create a lobby: choose the map, difficulty and mode yourself. The lobby gets a six-letter code that friends can type in, and the host can also invite friends directly. You can switch a lobby from private to public, but this cannot be undone. Players on the same Wi-Fi can also use local matchmaking without a code.

Players are numbered P1 to P4 in the order they join. The host can choose which map split the match uses. If someone disconnects they can rejoin a game that is still running.

Territories and map splits

Each player can only place towers inside their own territory. Common splits are horizontal, vertical or diagonal halves for two players and four quadrants for four. Three-player games use the four-player layout with one quadrant open to everyone. Some maps, including Firing Range and the Expert maps, are free for all by default, marked with an "A" for All. Hosts can also pick other splits, such as circle or square-in-square layouts.

A few rules follow from territories:

• You can only move your own towers, and a Support Chinook can only carry them inside your own area.
• Bananas and other collectables can only be picked up by the owner of the tower that made them.
• When a player leaves, their territory and remaining towers become available to the rest of the team.

Cash, XP and lives

Every player starts with less cash than in single player so the total stays fair: $550 each with two players, $500 each with three and $450 each with four. In Half Cash those cuts are halved too. In Deflation the $20,000 starting pot is split evenly and cash transfers are disabled.

During the game, money is shared across the team, so you do not need to fight for pops. Income from towers you own, such as Banana Farm bananas or Benjamin's per-round income, goes to you. Anyone can tap the co-op menu to request cash, and you can send cash to a teammate at any time. Hero XP is split evenly between every placed hero at the end of each round.

Lives are shared. If the team runs out, any player can pay for a Continue, except in modes that block Continues such as CHIMPS and Deflation.

Monkey Knowledge, heroes and Tier 5s

Monkey Knowledge is pooled: if one player owns a point, it applies to everyone, but the same point never stacks. If two players have Bonus Monkey!, each player still gets just one free Dart Monkey. Team-wide points only apply once, so Mana Shield gives the team one shield, not four. The More Cash bonus is also split between players instead of given to each.

Each player picks their own hero and has their own Tier 5 limit, so two players can each own a Tier 5 of the same upgrade. Some unique effects are still limited: only one Vengeful True Sun God can exist on the map, and many buffing Tier 5s (Sub Commander, Energizer, Prince of Darkness) do not stack their buffs when several players build them.

How towers interact between players

• Monkey Village and Alchemist buffs work on any player's towers. A shared Village is one of the best team investments.
• Overclock and Ultraboost can be used on a teammate's tower.
• Super Monkey Fan Club and Plasma Monkey Fan Club recruit Dart Monkeys from every player.
• Sun Temple, True Sun God and Paragon sacrifices can use other players' towers. Adora's Blood Sacrifice only takes her owner's towers.
• Admiral Brickell's mines can be placed on any water, regardless of territory.

Medals and rewards in Co-op

Co-op has its own medal set on every map, separate from single player, including Co-op Impoppable and CHIMPS medals. You can earn a medal for a mode you have not unlocked yet: join a CHIMPS lobby and win, and you get the Co-op CHIMPS medal even without Impoppable. Quick Matches sometimes produce combinations you cannot normally pick, such as Easy Reverse. Those pay Monkey Money but no medal.

The large first-time Monkey Money bonus is paid once per map and mode, no matter whether you earn it solo or in Co-op. Co-op CHIMPS has no Retry Last Round, so a win gives the black medal.

There are also Co-op Daily Challenges and Co-op Boss Events.

Tips for winning Co-op games

1. Agree on roles before round 1. One player takes early defence and camo, one farms, one builds MOAB damage. Use the emotes if you are in a random lobby.
2. Name the dangerous rounds. The emote set includes camo, lead, ceramic and MOAB icons for exactly this. Flag rounds 24 (camo), 28 (lead), 40 (MOAB), 63 and 76 (ceramic rushes) and 78 before they arrive.
3. Do not double up on unique buffs. One Village with Monkey Intelligence Bureau and one Alchemist stack well across the team; three copies of the same buff tower are wasted money.
4. Pick heroes that work at low level. XP is split, so heroes level slower than in solo. Bring a hero that is useful early, or let only one or two players place heroes.
5. Farm in the safest territory. The player furthest from the exit usually has the least pressure and should build the economy.
6. Send cash with a purpose. Pool money into one player's key upgrade (a Tier 4 or Tier 5) instead of spreading it into three half-built towers.
7. Keep fast forward in sync. If one player is struggling, slow down. A leak costs the whole team.

For examples of team setups, see our videos on the BTD6 Master YouTube channel.

Frequently asked questions

How do you play Co-op in BTD6?

Reach player level 20, then open Co-op from the main menu. Join a Quick Match or create a lobby and share its six-letter code with friends.

Is cash shared in BTD6 Co-op?

Yes. Money from the game is shared across the team, you can request or send cash at any time, and income from your own farms and similar towers goes to you.

Can you play CHIMPS in Co-op?

Yes. Co-op CHIMPS starts each player with less cash ($550, $500 or $450 depending on team size), and a win always counts as a black medal because there is no retry option.

Do Monkey Knowledge points stack in Co-op?

No. A point owned by any player applies to the whole team, but owning the same point twice does nothing extra.

Can two players have the same Tier 5 in Co-op?

Yes. Each player has their own Tier 5 limit. Some buffs do not stack, and only one Vengeful True Sun God can be on the map.

Do Co-op wins count for single player medals?

No. Co-op has its own medal set, and the first-time Monkey Money bonus is only paid once per map and mode across both.