This guide describes how to opt into a different Steam branch of Entropy : Zero 2 (EZ2) and some possible motivations for why one might wish to do so. It explains the differences between versions and the particulars of opting into a version.

Please let me know in the comments if this guide is helpful or if there is anything that could be clarified.

1. In your Steam library, find Entropy : Zero 2. Right click on it and choose "Properties" in the drop down.
   
2. In the properties window, select the "Betas" menu.
   
3. From the betas menu, you can opt into a beta branch.
   
4. There is a drop down for all branches. The default value is "None". Click on this drop down to see all possible branches.
   
5. You will likely want to select either the next or previous version. Find the branch with the name "release-X.X" where X.X is your desired version. If you would like to select the upcoming version, use the "upcoming" branch. The upcoming branch is always updated with the latest version in development for testing.
   
6. Select your desired version. You can exit the menu. Wait for Steam to redownload Entropy : Zero 2 before playing.
   
7. When you start up Entropy : Zero 2, make sure the version number on the menu matches the version you intended to opt into.

EZ2 publishes new builds onto beta branches for testing before pushing them to the default Steam branch. As of the writing of this guide, we make all our branches public (save for a singular obsolete development branch) and we have not cleaned up any branches from prior development.

This section of the guide will detail all the types of branches and why they exist.

• None - This is the default branch. This is what Steam will install if no beta version has been opted into. It is the latest stable version of EZ2.
  
• upcoming - Upcoming is a special branch which always points to the most recent build. It will typically match the most recent "release-X.X" branch. Set your build to 'upcoming' if you want to always get the latest unstable updates before they are released.
  
• release-X.X - These are branches representing each minor version of EZ2. Patch versions (0.0.X) are pushed onto the same branch as the last minor version. You can use release branches to either opt into an upcoming unpublished version OR to downgrade to a previous version.
  
• rc-X - RC or release candidate branches were used in the last two months leading up to the release to designate versions that might have become the final release. They are available for historical reasons only. You must enter the password "ez2archivist" into the Steam betas tab to see pre-release branches.
  
• beta-X.X - Beta branches were used prior to the release of EZ2. Please do not confuse "beta" in the name of these branches for Steam betas - these are older, pre-release branches. They are available for historical reasons only. You must enter the password "ez2archivist" into the Steam betas tab to see pre-release branches.
  
• alpha-X.X - Alpha versions cannot be found in Steam. The Entropy : Zero 2 alpha was what we called builds after the time at which the game was fully playable but before we published to Steam.

EZ2 versions, visible from the game's main menu, use a Major.Minor.Patch version scheme similar to semantic versioning[en.wikipedia.org].


EZ2 versions do not strictly follow semantic versioning because there will be odd circumstances where a minor version could break a saved game.

Here are the rules we're trying to follow internally for our semantic versions:

• Patch versions (0.0.X) can ONLY contain script changes (soundscripts, text changes) and not map or code binary changes
  
• Minor versions (0.X.0) must be incremented if any BSPs or DLLs change
  
• Major versions (X.0.0) are arbitrarily increased when the team decides a content is "major"
  
• Every build created must be pushed to a release branch corresponding with the first two digits (Major.Minor) Patch builds (0.0.X) overwrite the last build on the release branch

There are two main reasons why you would want to select a branch of EZ2.


If you would like to test out an update that the EZ2 team has not published, please feel free to opt into the latest release-X.X beta branch.

• WARNING: Once you have opted into a branch, you will not automatically receive all future updates beyond that Major.Minor version. You will need to manually update your branch at that point. You can always switch back to the "None" branch to always update to the latest.

Keep in mind also that even if you are on a version like version 1.0.0, if there is a patch version 1.0.1 in development, this will be published to the release-1.0 branch before being published to default. So opting into the release-1.0 branch does not mean switching to 1.0.0, but rather the latest upcoming patch version for 1.0.X.

If you do decide to test out an unpublished branch, thank you! Please report any serious bugs you find (Missing assets, crashes, regressions, etc) either on the Steam forums or in our Discord. If you do report a bug on an upcoming version, PLEASE include that in your post! We will need to know which version you are on when you encountered the issue.


Eventually, updates to EZ2 will break saved games. This is very undesirable, and the EZ2 team would like to avoid it if it is at all possible. But it is an inevitability with updates.

If you load an old save from a prior version of EZ2 only to find that the game is not working correctly, don't panic! You can preserve your save files by opting into the version you were playing before you saved the game.

Broken saved games will usually show up in a few predictable forms. The worst is when triggers appear as visible brushes when loading into a map - if you see this symptom, it is best to revert to a previous version. Other times you may have odd things like objects clipping into geometry that wasn't previously there. This could be breaking or non-breaking depending on the circumstances. One of the most common bugs you will find is an "AI Disabled" message. You can try to rectify it by running the console commands "ai_norebuildgraph 0; restart" and then loading your save again. If it still does not work, you may wish to try reverting to a previous version.

Read more on our troubleshooting guide:
https://gtm.you1.cn/sharedfiles/filedetails/?id=2857173498

It is highly recommended to include the version of EZ2 you were using when making a workshop addon in your addon description. This way, users will know when the addon was made and if there are compatibility issues with future updates, EZ2 can be reverted to a version that works with the addon.

Additionally, addons for fixes and improvements may be merged by the EZ2 dev team and added to the credits. When this happens, the addons may become obsolete - having the version listed in the description will be helpful for users.

To avoid confusion, we have hidden all of the branches from EZ2's development before it was released in August of 2022. These branches were prefixed with either "beta-" for beta versions of the game or "rc-" for release candidates as we approached release.
If you would like to opt into a pre-release version, use the beta password "ez2archivist".
Once you have entered the password, all of the pre-release versions should be visible.

These pre-release versions are not backwards compatible with the released version of the game. Switching to very old branches will likely cause issues with your installation. This option is only available for the purpose of archiving EZ2's development.

Our source code repository[github.com] is tagged with EZ2 versions.

These tags are created manually rather than automatically, so some of them have been missed historically depending on the circumstances.

Here are the general naming schemes for the Git tags:

1. EZ1vX.Y - Entropy : Zero 1 versions. Currently there are tags for EZ1v3.0 and EZ1v4.0. Prior to EZ1v3.0, our source code repository that is currently on GitHub was not set up.
   
2. ez2_release-X.Y.Z - Entropy : Zero 2 releases. These commits correspond to builds. Keep in mind that many patch version numbers will be skipped as patches do not contain code changes.
   
3. ez2_alpha-X.Y.Z - Entropy : Zero 2 alpha versions. We started using alpha version numbers after the game became fully playable from end to end and we could begin testing the whole game with blind playtesters. EZ2 alpha versions were source mods and were not published to Steam.
   
4. ez2_beta-X.Y.Z - Entropy : Zero 2 beta versions. The beta versions were published internally after we set up our Steam app.
   
5. ez2_rc-X - Entropy : Zero 2 release candidates. These were versions from the last few months leading up to the release that were considered candidates of our final code commits.