Why is regression testing important?

Because regressions, working behavior broken by a change, are uniquely damaging: they make updates feel like steps backward and erode player trust, and they ship silently because you tested the new feature, not the old thing you broke. Regression testing catches them before release, which is what makes frequent updates to a live game safe rather than risky.

What Is Regression Testing for Games?

Q: What is regression testing?

Re-verifying that existing, previously-working functionality still works after you make a change, to catch cases where a new fix or feature accidentally broke something. It guards against regressions, bugs in things that used to work, including old bugs being reintroduced, and is done via automated tests, manual checklists, or both.

Q: How can an indie do regression testing without a big test team?

Apply the principle proportionally: automate regression tests for the highest-stakes functionality (data integrity, progression, core mechanics, past painful bugs) and keep a manual checklist of critical behaviors to re-verify before release. Complement this with version-aware reporting that flags regressions in the wild, a previously-fixed bug reappearing on the new version stands out immediately so you can re-fix it fast.

Quick answer: Regression testing is the practice of re-checking previously-working functionality after a change, to ensure the change did not introduce a regression, a bug in something that used to work. It is how you guard against updates breaking existing features or reintroducing old bugs, run via automated tests, manual checklists, or both.

Every change you make to a game risks breaking something else, because code is interconnected and a fix in one place can have unintended effects elsewhere. Regression testing is the disciplined response: after a change, you verify that the things that worked before still work. It is less glamorous than testing new features, but it is what keeps every update from being a gamble, and what stops the frustrating cycle of fixed bugs coming back.

What Regression Testing Checks

Where testing a new feature checks that the new thing works, regression testing checks that the old things still work after you changed something. The target is existing, previously-correct functionality, the features, systems, and past bug fixes that were fine before this change. You re-run them to confirm the change did not inadvertently break them. The name comes from 'regression': a backward step where working behavior becomes broken.

Regression testing is especially focused on the areas a change might have affected and on the things that matter most if broken, core systems, past bugs that were painful, critical paths. You cannot re-test everything after every change, so good regression testing concentrates on the highest-risk and highest-importance functionality.

Why It Matters So Much

Regressions are uniquely damaging because they violate trust, a fixed bug returning or a working feature breaking makes updates feel like steps backward, which players come to dread. And they are insidious: you tested your new feature, not the old functionality you accidentally broke, so regressions ship silently and surface later through player reports. Regression testing is the defense that catches them before they ship.

For a live game shipping continuous updates, regression testing is what makes frequent updates safe rather than risky. Without it, every patch carries the danger of breaking something that worked, and over time uncontrolled regressions erode the game's stability and your players' confidence. With it, you can ship updates knowing you have verified the important existing behavior still holds.

Doing Regression Testing as an Indie

Big teams automate extensive regression test suites that run on every build. Indies rarely have that, but can apply the principle proportionally: automate regression tests for the things serious enough to warrant it (data-integrity, progression, core mechanics, past painful bugs), and maintain a manual checklist of critical behaviors to re-verify before release for the rest. Even a short, focused regression pass on your most important functionality catches the regressions that would do the most harm.

Field reporting complements pre-release regression testing by catching what slips through. Version-aware reporting flags regressions in the wild: a bug that appears only on the new version, especially one you thought was fixed, is a regression you just shipped. Bugnet tags every report and crash with its build version, so a previously-fixed issue that starts occurring again on the latest release stands out immediately, letting you catch and re-fix regressions fast even when a test did not cover them. Together, focused regression testing before release and version-aware monitoring after it keep regressions from accumulating.

Regression testing checks that your change didn't break what already worked. It's what keeps every update from being a gamble, and fixed bugs from coming back.