Versioning

For releases VCMI uses version numbering in form "1.X.Y", where:

'X' indicates major release. Different major versions are generally not compatible with each other. Save format is different, network protocol is different, mod format likely different.
'Y' indicates hotfix release. Despite its name this is usually not urgent, but planned release. Different hotfixes for same major version are fully compatible with each other.

Branches

Our branching strategy is very similar to GitFlow:

master branch has release commits. One commit - one release. Each release commit should be tagged with version 1.X.Y when corresponding version is released. State of master branch represents state of latest public release.
beta branch is for stabilization of ongoing release. Beta branch is created when new major release enters stabilization stage and is used for both major release itself as well as for subsequent hotfixes. Only changes that are safe, have minimal chance of regressions and improve player experience should be targeted into this branch. Breaking changes (e.g. save format changes) are forbidden in beta.
develop branch is a main branch for ongoing development. Pull requests with new features should be targeted to this branch, develop version is one major release ahead of beta.

Should be done immediately after start of stabilization stage for previous release

Create project named Release 1.X
Add all features and bugs that should be fixed as part of this release into this project

Should be done 2-4 weeks before planned release date. All major features should be finished at this point.

Should be done 1 week before release. Release date should be decided at this point.

Make sure to announce codebase freeze deadline (1 day before release) to all developers
Create pull request for release preparation tasks targeting beta:
- Update changelog
- Update release date for Linux packaging. See example
- Update build ID for Android packaging. See example
- Update downloads counter in readme.md. See example

Should be done 1 day before release. At this point beta branch is in full freeze.

Merge release preparation PR into beta
Merge beta into master. This will trigger CI pipeline that will generate release packages
Create draft release page, specify 1.x.y as tag for master after publishing
Check that artifacts for all platforms have been built by CI on master branch
Download and rename all build artifacts to use form "VCMI-1.X.Y-Platform.xxx"
Attach build artifacts for all platforms to release page
Manually extract Windows installer, remove $PLUGINSDIR directory which contains installer files and repackage data as .zip archive
Attach produced zip archive to release page as an alternative Windows installer
Upload built AAB to Google Play and send created release draft for review (usually takes several hours)
Prepare pull request for vcmi-updates
(major releases only) Prepare pull request with release update for web site https://github.com/vcmi/VCMI.eu

Should be done on release date