How to Fix the Shop Reroll Not Changing Items in a Roguelike

Paying to reroll a shop and getting the exact same items defeats the point. The shop must regenerate from a fresh RNG state each time, not from a cached or fixed seed.

How to fix it

1. Advance the RNG on reroll

Use the persistent run RNG stream for shop generation and let each reroll consume from it, so successive rerolls draw different items rather than restarting from the same seed.

2. Regenerate, do not reuse, the stock

Clear the cached inventory and rebuild it from the new RNG state on every reroll instead of returning the previously generated list.

3. Charge and gate the reroll

Deduct the reroll cost first and only regenerate if the player can afford it, optionally scaling the cost up per reroll on the same floor.

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.