Odyssey

An Odyssey is a chain of BTD6 games played back to back with the same limited crew. You pick your towers, Powers and one hero before you start, then sail through a series of islands, each with its own map, difficulty, mode and rules. The crew you choose at the start has to beat every island, and all islands share one pool of lives. That makes Odyssey a planning puzzle as much as a defense game.

Odyssey Events run every week with three Odysseys, one for each difficulty, and they are a steady source of Monkey Money, Trophies and Insta Monkeys.

How Odyssey mode works

Islands

• Easy Odysseys have 3 islands.
• Medium Odysseys have 4 islands.
• Hard Odysseys have 5 islands.

Each island is a full game with its own map, difficulty, game mode, round range and challenge rules. You play them in order and there is no freeplay after an island. Lose on an island and you can restart that island from its first round. At any point you can also reset the whole Odyssey and start again with a different crew.

Shared lives

All islands use one pool of lives, set by the Odyssey. Your starting lives are also your maximum. If you leak on an island, you can regain lives during that same game, but if you finish the island with fewer lives than you started, your maximum for the rest of the Odyssey drops to what you have left. Careless leaks early can therefore leave you with almost nothing on the last island. Islands played on Impoppable or CHIMPS do not change your lives.

Building your crew

The crew screen is where most Odysseys are won or lost. It has three parts:

• Hero seat: exactly one hero for the whole Odyssey.
• Monkey seats: each seat is one tower type. The number of seats (anywhere from 1 to 16) and the maximum total number of towers are set by the Odyssey. You then choose how many copies of each type to bring.
• Power seats: the same system for Powers, with 1 to 8 seats.

Here is how seats and copies interact. Say an Odyssey has two monkey seats and six max monkeys. You could bring two Dart Monkeys and four Boomerang Monkeys. On every island you can then place at most two Darts and four Boomerangs at a time. Adding a Bomb Shooter would mean removing a tower type entirely, because you only have two seats.

You only need to fill the seats you want. Insta Monkeys can be used only for tower types that have a seat, and each placed Insta counts as one of your copies.

Extreme mode

Some Odysseys are marked Extreme. In Extreme mode, every non-hero tower you place on an island is used up for the rest of the Odyssey. If you bring six Boomerangs and place two on island one, you only have four left for island two. Selling a tower gives you that copy back for the current island, but not for later ones. Extreme Odysseys reward using as few towers as possible on the early islands so you still have firepower for the final map.

How to pick a good crew

1. Read every island before choosing. Open each island's rules first. Note the maps, modes, round ranges and any special restrictions. A crew that is perfect for island one can be useless on a water map or in Magic Monkeys Only.
2. Cover Camo, Lead and MOABs. Every crew needs a reliable answer to Camo, Lead and MOAB-class bloons across all islands. Pick tower types that solve more than one of these.
3. Prefer flexible towers. Towers with three useful paths adapt to different islands. A versatile tower with several copies is often better than a specialist that only helps on one map.
4. Choose a hero that fits most islands. You cannot swap heroes between islands. A hero with strong early damage and some built-in Camo or Lead handling saves seats.
5. Fill Power seats with impactful Powers. Many Odyssey Events give you eight Power seats and up to 30 Powers, with a default set already equipped. Check the defaults and swap in Powers that cover your crew's weak spots.

Island-by-island tips

• Protect your lives early. Overbuilding a little on the first islands is cheap insurance, since lives lost there stay lost.
• Use the restart. If an island goes badly but you have not lost yet, restarting from the island's first round can save more lives than limping to the end.
• Mind the mode. Islands on Deflation, Half Cash, Apopalypse or Alternate Bloons Rounds need different plans. Event Odysseys can also use custom rounds, so do not assume standard round contents.
• Save Powers for emergencies. A well-timed Power on a dangerous round is worth more than one used to speed up an easy island.

Odyssey Events and rewards

The Odyssey Event usually starts on Thursday at 02:00 UTC and ends on the following Wednesday at 02:00 UTC. Each event offers an Easy, a Medium and a Hard Odyssey, each with its own setup and rewards.

• Completing an island gives the same Monkey Money as beating that map on that mode normally.
• Finishing the whole Odyssey adds a completion reward, usually Monkey Money plus a Power or an Insta Monkey.
• Completion also gives Trophies: 15 for Easy, 25 for Medium and 50 for Hard.

You can play all three difficulties for their rewards, but Trophies, medals and Collection Event items are not cumulative across difficulties. In practice, if you can only finish one, go for the hardest you can reliably clear. If you have time, Easy and Medium are quick extra Monkey Money and Instas.

The Odyssey Editor

Besides the weekly event, you can build and share your own Odysseys in the Odyssey Editor. Custom Odysseys have a fixed difficulty chosen by the creator, so other players cannot switch between Easy, Medium and Hard on them.

Odyssey guides on this site

Find crew suggestions and island walkthroughs in our Odyssey Event guides. For a full walkthrough, see our videos on the BTD6 Master YouTube channel.

Frequently asked questions

How many islands are in a BTD6 Odyssey?

Easy Odysseys have 3 islands, Medium have 4 and Hard have 5.

Are lives shared between Odyssey islands?

Yes. All islands use one pool of lives, and if you end an island with fewer lives than you started, your maximum lives drop for the rest of the Odyssey.

What is Extreme mode in Odyssey?

In Extreme mode, every non-hero tower you place on an island can no longer be used on later islands. Selling a tower only frees it for the current island.

Can I change my crew in the middle of an Odyssey?

No. To change your crew you have to reset the whole Odyssey and start from the first island.

Do Insta Monkeys work in Odyssey?

Yes, but only for tower types that have a seat in your crew, and each Insta counts as one of that tower's copies.

When does the Odyssey Event reset?

It usually runs from Thursday 02:00 UTC to Wednesday 02:00 UTC each week, with exceptions around major updates.