Quick answer: Give the character separate per-zone colliders (head, torso, limbs) each carrying its own damage multiplier, and read the multiplier from the specific collider that was hit.
Shooting an enemy in the leg deals headshot damage because the whole body is one collider. There are no real hit zones. Splitting the body into tagged colliders with per-zone multipliers fixes it. Here is how.
How to fix it
1. Build per-zone colliders
Attach distinct colliders for head, torso, arms, and legs, parented to the corresponding bones so they follow the animation. Each carries a component with its damage multiplier.
2. Read the multiplier from the hit collider
On a hit, get the zone component from the collider the raycast or projectile struck and multiply base damage by its factor (for example 2.0 head, 1.0 torso, 0.85 limbs).
3. Keep zones in sync with animation
Drive the colliders from the animated skeleton (ragdoll bones) so fast movement does not leave hit zones lagging the visible model and causing phantom or missed headshots.
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 Unity 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.