Firearm Malfunction Update

2026-11-11

Tags: OSR Be Not Afraid Firearms Mechanic

On occasion, my playtest version of a mechanic will become quite different to the blog version of it. Part of this is, of course, I’m quite slow to update the blog on some of the nuts and bolts stuff, but also because things just evolve in playtesting and I honestly forget I changed stuff.

I’ve already stated before that the Firearm Rules Compendium will be treated as a living document that gets updated as I change or modify things. That said, larger mechanical overhauls or updates might also get their own posts alongside updates to the primary article.

For the sake of comparison, I have the old version of the malfunction mechanics preserved if anyone is interested in those. I think the new version is a lot better.

Firearm Malfunctions

Whenever a firearm attack roll is a natural 1, and the weapon is of poor quality or is being used in adverse conditions (such as mud, sand, heavy rain, or similar environments), roll on the Weapon Jam Table.

2d6 Result Effect
2 Catastrophic Failure The weapon catastrophically fails. Make a Reflex Save or suffer Ballistic Damage equal to the weapon’s caliber. The weapon is broken and unusable until repaired.
3–4 Broken The weapon is broken and cannot be fired again until fully repaired.
5–7 Malfunction The weapon suffers a major malfunction. It requires 1d4 rounds to return to working order.
8–10 Jam The weapon jams and requires 1 Turn to clear before it can be fired again.
11–12 Minor Stoppage The weapon briefly malfunctions. Clear the stoppage immediately, but suffer −2 on the next attack made with the weapon.

Defunct Weapon Malfunctions

When to Check

If a player rolls a natural 1 In conditions where a weapon could feasibly malfunction, roll on the malfunction table. such conditions may include:

  • After submersion in water/mud
  • After sustained spray fire (10 combat rounds)
  • Using a Poor quality weapon
  • Using Poor quality ammunition

Malfunction Table

Roll 1d20 - Quality modifiers

Roll Malfunction Time to Fix Damage Risk
1-5 Misfire 1 round None
6-11 Failure to Extract 1 round None
12-17 Double Feed 2 rounds None
18-19 Severe Malfunction 2 rounds None
20 Broken Part Special None
21+ Catastrophic Failure Special Yes

Catastrophic Failure Details

Only possible on modified rolls of 24 or higher:

  1. Cracked Chamber
  2. Out of Battery Detonation (1d6 damage)
  3. Case Head Separation
  4. Catastrophic Failure (2d6 damage)