Mod Policy


We LOVE mods. Some of us started our careers as modders! We also loved Vortex Buffer’s multiplayer mod of Crypt of the NecroDancer so much, we turned it into an official expansion! So to help support our modding community, here are our “dos” and “don’ts” when creating mods with our titles.


We’re touched when folks take the time to create mods for our games. If you’d like to make a mod, all we ask is that you:

  1. DO NOT use any of our IP in a way that is offensive or exclusionary. We have zero tolerance for mods that are vulgar in nature, or that are disparaging based on someone’s identity, including race, gender, sexual orientation, culture, physical or mental abilities etc.
  2. DO NOT state or suggest that your mod is official, licensed, or otherwise authorized by Brace Yourself Games.
  3. DO NOT distribute a mod that is not your own, and do not distribute mods that include a full copy of any of our base games.
  4. DO NOT edit, delete, or create files outside of the following folders: primary user folder already utilized by the game, game installation folder or the operating system temporary storage locations unless optional to the user.
  5. DO NOT use mods to add advertisements or monetization features within our games.
  6. DO NOT circumvent integrity checks for unmodified gameplay, such as leaderboards and achievements, security measures to protect the user’s system and data, or ownership checks for DLC.
  7. DO distribute your mod for free. While you can accept donations for your work, you may not monetize your mod.
  8. DO follow our Terms of Use for our games!

We reserve the right to remove, without notice, any content that we feel violates our modding policy or fails to adhere to our rules and guidelines.


Take a few moments to read through and familiarize yourself with our modding etiquette guidelines.

  • Please remember that most people create mods as passion projects. They are not required to provide continued support for their mods.
  • Many modders welcome respectful feedback, but it’s up to the creator whether they make any changes or not.
  • Before you choose to modify and upload another person’s mod, ask them for permission and provide proper credit.
  • We cannot officially support mods containing assets from other games or media unless you have gotten express, written permission from the creator. In the case where no permission is granted explicitly, it will be assumed that no permission has been granted and may be removed at the request of the original creator.


Crypt of the NecroDancer: SYNCHRONY supports mods through

The desktop version of Crypt of the NecroDancer: SYNCHRONY includes built-in tools for creating and publishing mods. To ensure that all required metadata is in place, please use the in-game option for publishing your mod instead of manually uploading files on’s site.

By sharing a mod, you automatically make the full Lua source code and all related assets publicly available as a downloadable .zip archive on

Crypt of the NecroDancer refuses to load precompiled Lua bytecode, and runs mods in a sandboxed environment to restrict access to system resources. Mods must not attempt to circumvent these restrictions. Avoid obfuscating your code, as this makes it difficult to review what your mod does, making it very unlikely to receive cross-platform approval.


Every week, we feature some community mods in Crypt of the NecroDancer: SYNCHRONY. Featured mods are selected after a two-step process.

Step 1: Technical Review

All mods submitted through are subject to a technical review, which ensures that mod creators don’t try anything untoward from a copyright, content, or security perspective. 

This is a manual process, and we monitor changes and approve versions incrementally. While all public mods are immediately available on Windows, MacOS and Linux, passing this review is required for a mod to be playable on consoles. Once the list of supported platforms on the mod’s page includes Nintendo Switch and PlayStation, it has passed the technical review and can be enabled in console/cross-play lobbies.

Step 2: Weekly Curation

The game periodically fetches data from our servers to determine which mods, custom rules, and characters are part of the current Weekly Challenge. We may combine multiple mods, and we may also ask modders to include weekly-specific tweaks in the form of custom rules, to alter gameplay for the Challenge. All Weeklies are locked to a single character with fixed custom rules. Highscore and Speedrun leaderboards are available for each week and continue to be available even after each week has ended.

Weekly Challenges are updated every Wednesday, and are usually chosen about two weeks in advance by a member of the Vortex Buffer or Brace Yourself Games team. The version numbers of all included mods are locked in shortly before being featured, and any mod updates published after that point in time will not be reflected in the Weekly Challenge.

There is no explicit submission process for console approval or being featured in the Weekly Challenge, though we may reach out to modders who created mods that are almost suitable (but may be missing non-AMPLIFIED compatibility, or are using a copyrighted asset somewhere, etc.)

We reserve the right to change any data or make any substitutions at any time in case a mod is found to violate any of our terms or policies. If a mod you created has been featured and you would like us to remove it, please email [email protected].

Criteria for Weekly Challenge featured mods:

In general, anything from slight gameplay tweaks to total conversions is considered for inclusion in the Weekly Curation. That said, we prefer mods that feature original content. In addition to the rules listed at the beginning, your mod:

    • SHOULD be around (or at most slightly above) Cadence All Zones difficulty
    • SHOULD be fun for both speedruns and score runs
    • MUST be compatible with both AMPLIFIED and non-AMPLIFIED sessions
    • MUST be compatible with online multiplayer
    • MUST abide by our modding rules.
    • MUST be fully playable on keyboard and controller (avoid custom key bindings)
    • MUST NOT introduce any security issues (i.e. can’t include any means of activating chat on consoles)


Q: Creating mods is a lot more work than I thought! Could I add a donation button to my website, or start a Patreon/Ko-fi for people who want to support me?
A: Yes, absolutely! We fully support optional donations to modders and their work if our other policy requirements are met. If you liked a mod someone has made, consider sending them some support!

Q: Can I accept money for a mod commission?

A: Yes, we have no problem with modders accepting commissions. However, we strongly encourage you to protect yourself and your agreement by negotiating and signing a contract before you accept a commission. If accessible, it may be worth getting a legal consult to help you spot not-so-friendly contract clauses that may be hard to identify if you’re not familiar with contract law, or don’t have as much experience with contracts.

Q: Could my mod ever get turned into an official DLC?
A: Our collaboration with Vortex Buffer for SYNCHRONY was kind of a perfect storm. It’s unfortunately very unlikely to happen again!

Q: I REALLY want my mod to be featured in Crypt of the NecroDancer’s Weekly Challenge!
A: We can’t guarantee that your mod will be chosen, but if it meets all of the criteria, please feel free to share it in spaces like our Discord, where we are very likely to see it.

Q: I found a bug or have some feedback for a mod someone made.
A: Sorry, we can’t help you there! You’ll need to take that up with the mod’s creator. For SYNCHRONY, each page has a comment section specifically for giving feedback and reporting bugs. On PC, you can open the page for any installed mod by right clicking or pressing ‘Tab’ on a mod, then selecting “View on“. The comment section can be found below the mod description on the page.

Q: I discovered a mod that was inappropriate or offensive. What can I do?
A: You can submit a report using the in-game reporter, or email us with the details at [email protected]