Roblox Undertale Adventures X, developed by Side Productions and formerly known as Undertale Adventures TD, challenges players to defend their Underground base from waves of monsters using units inspired by Undertale. Redeeming promotional codes provides valuable supplies such as trait rerolls, summons, souls, and upgrade materials to help enhance your towers.
Working Undertale Adventures X Codes (October 2026)
Last checked October 13, 2026 · 8 sources · 6 working codes.
| Code | Reward | Status | First reported |
|---|---|---|---|
2KCCU! | Freebies | Confirmed | Before October 13, 2026 |
FREESTUFF! | Freebies | Confirmed | Before October 13, 2026 |
UPDATEJUNE10 | - | Reported | Before October 13, 2026 |
SORRYAFTERTALEDELAY | 3 Rerolls | Disputed | Before October 13, 2026 |
UPDSEP25! | Rerolls | Disputed | Before October 13, 2026 |
XMASUPDATE2025 | Rerolls | Disputed | Before October 13, 2026 |
Expired Undertale Adventures X Codes
| Code | Reward | Status | First reported |
|---|---|---|---|
HOTLANDS2025 | Not stated | Likely expired | October 13, 2026 |
JUNE10UPDATE | 30 trait rerolls | Likely expired | October 13, 2026 |
THANKYOU10kMEMBERS | Not stated | Likely expired | October 13, 2026 |
THANKYOU12MILLIONVISITS | one justice vial, one magu fruit, and one empty gun | Likely expired | October 13, 2026 |
THANKYOUFORWAITING | Not stated | Likely expired | October 13, 2026 |
WELOVEUAPLAYERS | Not stated | Likely expired | October 13, 2026 |
WINTER2025 | Not stated | Likely expired | October 13, 2026 |
Sources
How to Redeem Codes in Undertale Adventures X
Claiming developer rewards in Undertale Adventures X takes only a few seconds through the in-game interface. Follow these steps to redeem your codes:
- Launch Undertale Adventures X on the Roblox platform.
- Click the Codes button located on the right side of the screen.
- Type or paste your code into the redemption text box.
- Press the Enter key on your keyboard or select Redeem to submit the code and receive your rewards immediately.
Why Your Codes Might Not Work
If the game does not accept an entry, check for the following common issues:
- Case sensitivity: Codes require exact matching, including capital letters, numbers, and punctuation marks such as exclamation points. Entering them with altered casing will cause an error.
- Accidental spaces: Copying text often captures extra spaces at the beginning or end of a string. Make sure the text box contains only the exact code characters.
- One-time use: Each code can only be claimed once per Roblox account. Attempting to enter a previously claimed code will result in an invalid notification.
- Expiration: The developers at Side Productions disable older codes when new updates launch or event periods end. Expired codes cannot be reactivated.
- Server version desynchronization: When a brand-new code is released alongside an update, older game servers may not recognize it immediately. Leaving the game and joining a different server often connects you to an updated build where new codes function properly.
Where to Find More Undertale Adventures X Codes
Side Productions releases new reward codes during major content patches, milestone celebrations, and special community events. You can monitor official channels directly for news and drops:
- Join the official Side Productions Roblox Group.
- Join the Side Productions Discord server, where update logs and announcements are posted.
Frequently Asked Questions
Can Undertale Adventures X codes be redeemed multiple times?
No. Reward codes in Undertale Adventures X are single-use per Roblox account. Once an account claims the items tied to a specific code, that code cannot be redeemed again by the same player.
Where is the code button located?
The Codes button is on the right side of your screen while inside the game lobby or active interface.
What should you do if a newly announced code does not work?
If a code was just posted by the developers but fails in-game, close the game client and rejoin. This ensures your character enters an updated server instance running the latest game build.
