What causes an elemental weakness multiplier applied twice?

For an attack with two element tags you look up each element's multiplier and multiply them together, so hitting a single weakness through two tags squares the bonus.

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 Elemental Weakness Multipliers Stacking Twice in Unreal

Quick answer: Resolve the effective element of the attack once, or take the maximum weakness multiplier among the attack's elements rather than the product, then apply it a single time.

An ice/water spell hitting a fire enemy should not deal 2x times 2x equals 4x damage. If yours does, you are multiplying per-element multipliers. Here is how to combine them correctly.

How to fix it

1. Decide a combine rule

For multi-element attacks pick one rule: usually take the strongest weakness with FMath::Max, not the product, so a double-weak hit is 2x not 4x.

2. Apply the multiplier once

Compute the final element multiplier first, then multiply base damage by it exactly one time at the end of the damage formula.

3. Separate weakness from resistance

Resolve weakness and resistance into a single signed affinity value per element so an enemy that is weak to one tag and resistant to another nets out predictably.

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 Unreal Engine 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.