Quick answer: Soak testing (or endurance testing) is running a game continuously for a long duration, hours or days, to surface problems that develop slowly over time. It catches issues like memory leaks, resource accumulation, and performance degradation that are invisible in short test sessions but break the game during extended play.
Most testing happens in short bursts, a few minutes here and there, which is exactly why a whole class of bugs escapes it: the ones that only appear after the game has been running for a long time. Soak testing is the antidote, running the game continuously for hours or days to catch the slow-developing problems that accumulate over time. For games where players have long sessions, soak testing catches the bugs that short testing structurally cannot.
What Soak Testing Catches
Soak testing targets time-dependent and accumulation problems, issues that are not present at the start but develop as the game runs. The classic example is a memory leak: memory that slowly accumulates until, after a long enough session, it exhausts available memory and crashes. Other examples include resource handles that pile up, performance that gradually degrades, numbers that overflow after enough time, and any state that drifts or accumulates over extended operation.
The common thread is that these problems are invisible in short testing. A memory leak that takes two hours to cause a crash will never appear in a ten-minute test session, the game seems perfectly stable. Only by running for an extended period does the slow accumulation reach the threshold where it causes a visible failure. Soak testing deliberately creates that extended duration to surface these otherwise-hidden issues.
Why Soak Testing Matters
Players have long sessions, hours of continuous play, especially in immersive genres, and a game that is stable for ten minutes but crashes after three hours is broken for those players. Soak testing matches the test duration to real player behavior, catching the issues long-session players will hit. Without it, these problems escape to players and generate the frustrating 'crashes after I've been playing a while' reports that are hard to diagnose and that short internal testing would never reproduce.
These slow-burn issues are also among the trickiest to diagnose from the field, because the symptom (a crash after hours) is far removed from the cause (a small leak each frame), and the reports are vague about triggers. Catching them proactively through soak testing, rather than reactively from confusing field reports, saves a great deal of diagnostic pain. It is the structured way to find the bugs that only time reveals.
Soak Testing and Field Monitoring
Soak testing during development is the proactive defense, but the field is the ultimate soak test: real players running the game for durations and in patterns you cannot fully replicate. So soak testing pairs naturally with field monitoring that catches the time-dependent issues that slip through. The signature in the field is distinctive, crashes correlated with long session length, often out-of-memory crashes that point at a leak.
Bugnet captures device context including memory information and session-relevant detail, and groups crashes by signature, so the field equivalent of a soak-test failure, an out-of-memory crash clustering among long sessions, surfaces as a recognizable pattern pointing at a leak or accumulation problem. Combining proactive soak testing (to catch these issues before release) with field monitoring (to catch the ones that escape, correlated with session length) gives you coverage of the time-dependent bugs that short testing structurally cannot find, the slow accumulations that only a long-running game reveals.
Soak testing runs the game for hours to catch what only time reveals, leaks and slow accumulations a ten-minute test never sees. Players have long sessions, so should your testing.