What causes item rarity weights being ignored on drops?

Items are chosen with uniform random selection over the pool instead of a weighted roll, so rare items appear as frequently as common ones.

How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix Rarity Weights Being Ignored When Rolling Items

Quick answer: Roll a rarity tier first using per-floor weights, then pick uniformly within that tier, so the rarity distribution matches your intended drop rates.

When legendaries drop as often as commons, your selection is uniform, not weighted. Rolling the rarity tier by weight first and then the item within it restores proper drop rates.

How to fix it

1. Roll rarity by weight first

Build a weighted table of rarity tiers (e.g. common 70, rare 25, legendary 5), roll a tier against the total weight, then pick a random item within that tier.

2. Vary weights by floor

Increase rare and legendary weights on deeper floors so late-run rewards skew higher, using a per-floor weight table rather than a fixed one.

3. Verify the distribution

Simulate thousands of rolls in a test and assert the observed tier frequencies match the configured weights so a miswired table is caught early.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every GameMaker error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.

Reproduce it once with full context and the fix writes itself. The hunt is the expensive part.