The Challenge Editor is a feature in BTD6, first added in Version 9.0. It allows players to create challenges with special rules and restrictions, then share them with others. The Challenge Editor also comes with its own virtual game mode where players can emulate gameplay of almost any game mode with custom scenarios (excluding enabled Powers or using paid Continues), the main highlight that being the freedom to press "Retry last round" to restart a round without needing to restart the entire current game.
There are 19 factors:
- Name (up to 40 characters)
- Map (one map out of all maps unlocked by the creator)
- Difficulty (Easy, Medium, Hard)
- Gamemode (Standard, ABR, Reverse, Impoppable, Deflation, Apopalypse, Double HP MOABs, Half Cash, CHIMPS)
- Starting Cash ($1 to $10,000,000)
- Starting Lives (1 to 10,000,000)
- Max Lives (1 to 10,000,000)
- Start Round (1 to final unlocked round, up to 300)
- End Round (1 to final unlocked round, up to 300)
- Heroes (Selectable or Pre-Selected)
- Towers (Dart Monkey, Boomerang Monkey, Bomb Shooter, etc; quantities from 1 to 99, infinite, or disallowed)
- Upgrades (0 to 5 for Path 1, 0 to 5 for Path 2, 0 to 5 for Path 3)
- Max Towers (1 to 99, or infinite)
- Bloon Speed (5% to 500%)
- MOAB Speed (5% to 500%)
- Ceramic Health (10% to 2000%)
- MOAB Health (5% to 2000%)
- Regrow Rate (5% to 1500%)
- Powers (enabled/disabled)
- Monkey Knowledge (enabled/disabled)
- Continues (enabled/disabled)
- Selling (enabled/disabled)
- Regrow Bloons (disabled/enabled, affects all bloons including bloons spawned from MOAB bloons)
- Camo Bloons (disabled/enabled, affects all bloons including bloons spawned from MOAB bloons)
- Enable Double Cash (disabled/enabled, disabling this option disables Double Cash)
Testing and Sharing a Challenge
Challenges can be tested once challenge modifiers are decided. To start testing the challenge, press the new game/continue game button. Powers are disabled during the test run. If all lives are lost during a test run, it is possible to restart from the last round played, with all money, towers, and lives set back to where it was (in other words, the game instantly reloads the last saved round).
After winning the test run, the challenge can be shared. Click the share button to share. It will provide a code to share that can be copied and pasted. Challenge codes will last forever, so there is no worry about creating a new challenge without losing the previously made challenge. Challenge codes will generally feature a string of capital letters approximately 7-8 characters long.
Prior to Version 22.0, it was possible to submit challenges directly to Ninja Kiwi via the game, which could be submitted to them at the difficulty of Easy, Medium, Hard, or Friday Stinger (and also be submitted anonymously if the user doesn't intend to have their name next to their challenge).
Note that one can still play a Custom Challenge that was made on an earlier version of the game, but not if the Custom Challenge was made on a later version of the game than the user's current game version. However, balance changes may make previous challenges much easier, harder, or even impossible to complete.
The Challenge Browser was introduced in Version 22.0. It can be accessed from the same news board as Daily Challenges and Advanced Challenges. Players are shown a list of shared challenges, which can be sorted by the following criteria:
- Most Liked
- My Saved Games
- My Challenges
On the list, a challenge includes a map preview, name, uploader's profile picture and name, amount of likes, clear rate, favorite button, and a checkmark indicating whether or not the player has completed it. Once another user's challenge is attempted or beaten, it can be liked and/or favorited.
"Trending" lists popular challenges, "Newest" lists the most recently created challenges. "Most Liked" lists the challenges that have the most likes. "Casual" challenges are defined in-game algorithmically as challenges with a general high win-rate, and conversely is applied for "Expert" challenges.
The player can use the "Favorites" lists to access all challenges that they have put a "favorite" for. The "favorite" button is a pink heart icon.
The "My Saved Games" category is where multiple saves for challenges are stored. There is currently no known max to the number of challenges that can be stored at any one time.
The player can access My Challenges to access all challenges that they have created, including those made before Version 22.0. It is possible to delete their own challenge by pressing the red "no-entry" button on the left of their challenge. Tapping that button will prompt the request to delete the challenge ("delete this challenge permanently?"), to where the player can then press "cancel" or "OK".
The clear rate (also referred as the "win rate") is marked as a percentage of players who had completed the challenge. If at least one user has completed the challenge, besides the initial challenge testing made by the creator themselves, then the challenge will display at least a "<1%" clear rate. If any player loses on a challenge, the challenge clear rate is listed as ">100%" at max.
Tapping on the clear rate reveals the defeat rate, marked as a skull icon instead of a trophy icon. The defeat rate is not the inverse of the clear rate; rather, it marks the number of defeats over the total number of attempts in the game. This can be somewhat useful in seeing how many times the challenge has been attempted. This feature was added since Version 23.0.
Version 24.0 adds yet another functionality that allows public viewing of statistics of a challenge's completion rate, defeat rate, number of successful players, and so on. (check proper stats?) In addition, challenges made since Version 24.0 will have a feature to record the first and most recent players to complete the challenge under non-emulation conditions.
Tips on making challenges
- Try making an interesting challenge that balances time duration and enjoyability together. Avoid making challenges that take excessive amount of time and/or luck to play.
- Do apply restrictions to challenges, such as limiting towers and/or their upgrades, to reduce the chance of players "cheesing" a challenge.
- Sometimes, a challenge can become even more fun if the challenge limits Monkey Knowledge, Powers, selling, or income.
- It is strongly advised to make a challenge with Monkey Knowledge disabled if Crossbow Master disabled, as double Crossbow Master is an extremely powerful combo that may trivialize certain challenges.
- Sometimes, when restarting a round in the Challenge Editor, the player loses money from the last bloon popped from the last round. While this is usually negligible, using a tower that destroys a large amount of bloons at the same time - such as Ground Zero or Tsar Bomba - can cause large amounts of money to be lost. It is unknown when this bug was introduced and this bug was patched on Version 15.0.
- u/DaScavenger found out how many challenge combinations are possible (pre-10.0). Link.
- Due to the fact that Ceramics can have 20x the health, a "super ceramic" can have 1200 health, 3x stronger than a MOAB's outer layer.
- With ramping changes, a Round 100 BAD can have 1,120,000 HP with 20x MOAB health and the submode Double HP MOABs.
- When Version 10.2 came out on Steam and not for Mobile, it became impossible to play challenges made on Steam to Mobile (which at the time is Version 10.1). This was fixed with the release of version 11.0.
- The challenge name input was founded to be in Unity's rich text format, and thus it used to be possible to include tags such as <b>, <i>, <u>, <s>, <br />, <sup>, <sub>, <color=>, and <size=> to add effects to the titles. Although this discovery took place in version 11.0, these tags likely worked on previous versions of the game. This bug was fixed on Version 12.0.
- As of Version 21.0, it is confirmed that a challenge name filter has been added, after a user on r/btd6 asked about a previously unfiltered name. Much earlier, as shown in one of ISAB's videos, a user made a challenge named "You Can Swear in Challenge Names", and although the word he inputted was not filtered, the user who made that challenge already knew that offensive words (specifically profanity) could be inputted.
- Version 22.0 featured a bug when Regrow Rate was first released, and its lower value was temporarily increased to the base 100% until around Version 23.0 or so. From then, the minimum Regrow Rate was once again reduced back to 5%.
- According to Ninja Kiwi's July 30th 2021 blog, custom rounds in challenges for users is planned but confirmed officially to be very difficult to implement in practice.
- When searching using the search bar, the dropdown menu has an extra "Custom" option. This goes away when selecting a new dropdown option.
- The name "Pretty Simple" is strangely filtered out for no specific reason, although it is likely because of a false positive to countermeasuring grey area countercensorship. Link.