Quick answer: Procedural content has unique bug surface - infinite combinations, seed-dependent bugs. A bash that varies seed and explores combinations finds bugs targeted at the system.
Procedural systems generate the bugs; testing them needs procedural test plans.
Seed sweep
Test seeds 1, 100, 1000, 10000. Each generates different content; bugs surface.
Combination focus
Pair seeds with biome, character class, time of day. Combinations explode bug surface.
Verify edge cases
Seed 0; seed MAX_INT; negative seeds. Edge cases hide bugs.
Tag procedural bugs separately
'Procedural-only' tag. Triage knows; engineers understand context.
“Procedural bugs are seed-dependent. Test the seed dimension.”
If your game has procedural generation, the seed-based bash is a quarterly cadence. Document; reuse.