Undertale Adventures X Codes — Roblox (Checked October 20, 2026)
There are 4 working Undertale Adventures X codes on October 20, 2026: PREPAREFORHALLOWEEN, 6KCCUREWARD, 5KCCUREWARD and MOREFREESTUFF. They give Trait Rerolls, Gaster Hands, Souls and Halloween items. To redeem them in the Roblox tower defense game Undertale Adventures X (formerly Undertale Adventures TD), press the Codes button on the right side of the lobby, type a code exactly as shown and press Enter. If a brand-new code fails, rejoin so you land on an updated server.
Working Undertale Adventures X codes (checked 2026-10-20)
| Code | Reward | Added |
|---|---|---|
PREPAREFORHALLOWEEN |
10 Temmie Flakes III, 25 Soul Fragments, 1 Bravery Vial, 1 Temmie Flakes IV and more | October 19, 2026 |
6KCCUREWARD |
50 Trait Rerolls, 15 Gaster Hands, 5 Glamburgers, 1 Temmie Flakes V, 5 Face Steaks and more | October 19, 2026 |
5KCCUREWARD |
50 Trait Rerolls, 15 Gaster Hands, 5 Glamburgers, 1 Temmie Flakes V, 5 Face Steaks and more | October 19, 2026 |
MOREFREESTUFF |
25 Trait Rerolls, 3 Gaster Hands, 1,000 Souls | October 15, 2026 |
All four were working on October 19–20, 2026. The 5KCCU and 6KCCU codes celebrate 5,000 and 6,000 players online at once.
Disputed codes
2KCCU! and FREESTUFF! work for some players and not for others. They may only work on old servers, so they're worth one try.
How to redeem Undertale Adventures X codes
- Open Undertale Adventures X on Roblox.
- In the lobby, press the Codes button on the right side of the screen.
- Type or paste a code into the box. Capital letters and punctuation (such as the ! in 2KCCU!) must match exactly.
- Press Enter (or the confirm button on mobile/console). The reward is added right away.
Why an Undertale Adventures X code isn't working
- Old server. New codes arrive with updates. If a code from today fails, leave and rejoin (or join a different server) so you're on the updated build.
- Typo, case or a stray space. Copy the code from the table instead of typing it.
- Already used. Each code works once per account.
- Expired. See the list below.
Expired codes
These no longer work: XMASUPDATE2025, UPDSEP25!, SORRYAFTERTALEDELAY, THANKYOU10kMEMBERS, THANKYOU12MILLIONVISITS, JUNE10UPDATE, HOTLANDS2025, WINTER2025, WELOVEUAPLAYERS, 3KCCU!, 4KCCU!, UAXISTHEBESTUTTD, THANKYOUFORWAITING, TRADINGSOON!, MONEYTONIGHT.
When new codes come out
Side Productions has released codes in three ways: player-count milestones (2KCCU! through 6KCCUREWARD), big updates and events (PREPAREFORHALLOWEEN, XMASUPDATE2025) and apology codes after delays or shutdowns (SORRYAFTERTALEDELAY). They're announced in the game's official Discord and the Side Productions group. With Halloween coming and the game near new player records, more codes are likely soon. We check every day.
About the game
Undertale Adventures X is a Roblox tower defense game by the group Side Productions. You defend your base in the Underground from waves of monsters with units inspired by Undertale, level them up and give them traits. It started in 2024 as Undertale Adventures TD and relaunched as Undertale Adventures X. By the evening of October 20, 2026 it had about 19.6 million visits and 41,600 favorites, with more than 4,000 people playing at once. It's a fan-made game and isn't made by Toby Fox.
Changelog
- October 20, 2026: page published with 4 working codes, 2 disputed codes and 15 expired codes.
Frequently asked questions
What are the Undertale Adventures X codes?
As of October 20, 2026 there are 4 working codes: PREPAREFORHALLOWEEN, 6KCCUREWARD, 5KCCUREWARD and MOREFREESTUFF. 2KCCU! and FREESTUFF! are disputed and may only work on old servers.
How do you redeem codes in Undertale Adventures X?
Press the Codes button on the right side of the lobby, type the code exactly as written and press Enter.
Why is my Undertale Adventures X code not working?
New codes often fail on servers that started before the update. Rejoin or switch servers, check capitals and the ! mark, and remember each code works once per account.
What is the best Undertale Adventures X code?
5KCCUREWARD and 6KCCUREWARD, which each give 50 Trait Rerolls and 15 Gaster Hands plus items.
Is Undertale Adventures X the same as Undertale Adventures TD?
Yes. Undertale Adventures TD was renamed Undertale Adventures X when it relaunched. Old TD codes are expired.
Who made Undertale Adventures X?
The Roblox group Side Productions. It's a fan game inspired by Undertale, not an official Undertale game.
When do new Undertale Adventures X codes come out?
Usually with updates, events such as Halloween and Christmas, and when the game hits player-count milestones. They're posted in the official Discord.