Advice For New DMs/GMs - "Crits & Fumbles".

Copyright © Mark Kelly 2025

Much time has passed since last I posted on the topic of my one, true gaming love: traditional pencil & paper role playing games. In many ways this post is reconnecting to my original purpose for creating this blog back in March of 2011: to help, advice, guide and share with budding and novice Dungeon Masters and Games Masters alike - even seasoned DMs & GMs are most welcome, even players, because today's player is tomorrow's DM/GM.

On a personal note, it's been a couple of years now since I last touched the dice and hid behind the shield of a DM's screen, and yes, there are times I yearn to be there again. One obstacle, though - finding your player base. But I'll leave that for another day (or evening) and another post.

As the title states, I'll be going over the Critical Roll - "the Crit", and its counter-part, the Failed Roll - "the Fumble".

Different game systems approach this subject differently, with the terminology, game mechanics, and the required dice involved. As a player, I'd guess the amount of actual game time spent as a player possibly amounts to, maybe, roughly a year? But as a DM/GM, my time is almost thirty years. Over that period I've covered multiple game systems, listed below:

1. Dragon Warriors.
2. Advanced Dungeons & Dragons.
3. Warhammer Fantasy Role Playing Game.
4. Traveller (original).
5. Call of Cthulu.

Not a massive library of games, I'll admit. But time spent in games 1 - 3, was extensive, and highly enjoyable.

As a side note - once players find a game system they resonate with and visualise the best, it's usually the one they will play the most and return to, even after exploring other game systems. As a prime example, my group experimented with sci-fi (Traveller), but preferred the fantasy setting and genre. For others it can be the reverse. I assume it is linked with their first exposure to a role playing game/system and the 'imprinting' it has on their gamer's brain. By the same token, much of that also has to do with the DM/GM and how good a job they do. If the person running said game is bad at it, that in itself can put new players off.

Below is a table showing the game system I've listed and their respective game mechanics in respect to crits and fumbles.

Game	Critical Hit System	Fumble System	Dice Used
Dragon Warriors (1985)	Natural 1 on a d20 = Critical Hit (automatic hit, often max damage).	Natural 20 on a d20 = Fumble (dropped weapon, self-harm, or breakage).	d20 for attack rolls.
AD&D (1e/2e)	No official crits in core. Unearthed Arcana (1e) & house rules: natural 20 on d20 = double damage. 2e Combat & Tactics adds crit tables.	No official fumbles. House rules often: natural 1 on d20 = dropped/broken weapon.	d20 for attack rolls; damage dice vary by weapon (d4–d12).
Warhammer Fantasy RPG (1e–4e)	When reducing enemy to 0 Wounds, roll d100 on Critical Hit Tables (severed limbs, bleeding out, etc.). “Ulric’s Fury”: exploding 10s on d10 damage.	Fumbles: usually d100 roll of 96–00 = dropped weapon or misfire. Black Powder weapons use special misfire charts.	d100 for skill/attack rolls; d10 for damage.
Traveller (Classic & Mongoose)	Classic: no crits. Mongoose: Effect 6+ (beat target number by 6 or more) on 2d6 = critical hit with bonus damage/effects.	No universal fumbles. In Mongoose, natural 2 on 2d6 often = mishap, adjudicated by Referee.	2d6 for skill/attack checks.
Call of Cthulhu (7e)	Critical Success = rolling exactly 01 on d100 (or ≤1/5 skill, depending on edition).	Fumble = rolling 100 (or 96–100 if skill <50%) on d100. Mishaps vary by GM.	d100 (percentile dice) for all skill checks.

As shown above, the die used vary dependant on which game system is being played, ranging from D6, D20 to D100 (2 x D10 for those unfamiliar, one D10 being 'tens' and the other being 'units').

But this is where we diverge, or at least, this is where I diverge. 

IT'S NOT ALWAYS ABOUT COMBAT.

Criticals and Fumbles are almost always associated with combat, but can also be assigned to pivotal task-driven rolls, again, usually dictated by the game system in play.

Allow me to throw some examples of non-combat situations:

A thief in a fantasy setting is attempting to gain access into a secret chamber, knowing full well the door is bristling with counter measures should their lock picking attempt fail - should said thief fail, then the DM makes their roll behind the screen: if they roll the equivalent of a 'crit', say 00 on the D100, denoting 100% activation of the door traps, it's a 'crit' and the poor thief becomes a pin cushion of poisoned darts.
Should the DM's D100 come up with a 01, then the traps have failed, 'fumble' - and the thief grimaces as the door traps click and whirr and do nothing more.

Or...

The players are out-running a group of security guards on the rooftop building of a Mega Corp. Rounds fired from the weapons of the pursuing guards whizz by the fleeing players' heads, smacking venting ducts and communication poles. Now there's a drop in rooftop levels. It's fifteen feet and quickly the players drop one-by-one, bullets smacking the area around them, the yells of security getting closer.

Each player has to make a roll to ensure their landing is safe and they escape.

Two D6 are rolled and the last player rolls a natural 2. So now it is a failed 'success' roll, in essence. A fumble on landing. Is the character's ankle twisted? Broken? On the flip side, a player who rolls a natural 12 for their character would be told how they roll smoothly, absorbing all the shock of the landing, rising to their feet and running in one fluid move - success, akin to a 'critical' result.

MAKE IT EXCITING

The whole crit & fumble action can be clinical, dry and sanitised experience if handled as a die rolling exercise and focusing on the rules and regulations of the rule book.

Every player thrills at rolling a crit when it really matters, and dreads a fumble in that very same moment. How a DM/GM handles this situation is the difference between a high-tension, adrenalin-fuelled exciting scene and a massive anti-climax.

Which of the following, if you were the player, would you prefer?

"Your breathing is ragged, and you gulp for air. The warmth of your life blood spreads under your battered armour, but you grip tightly onto your sword. You are the last hope to save your fallen comrades, as you glance at their bodies strewn about the chamber, not knowing who is dead or alive.

The Chamber's Guardian, though burned by spell and hacked by sword, still glares at you with a bloodlust as it hefts its double-headed axe, preparing to end your life, charging at you with a roar."

Behind the screen the DM knows one solid hit from the remaining character will fell the Chamber Guardian, who has only 6 points of health left, but he also knows that should the player fail and the Guardian's attack land, then it's the end of the party, and the player's also know this as their last hope only has 4 points of health left, and the Guardian's double-headed axe inflicts 10 points of damage.

Statements of intent are announced, and the initiative rolls are made. It's a split initiative, both DM and player have rolled the same. This means, even though the player will roll first, the Guardian also gets to strike, even if it means death to both, the strikes are deemed as simultaneous.

The player rolls... natural 20, the table erupts. The DM allows them to have their moment. The players settle down, realising it could still end badly if the Guardian get to hit.

THE SCENE.

The DM rolls, it's a 10 - a miss, but close. So the DM goes into describing the final clash:

"The Guardian's bulk moves with surprising speed, the huge axe arcing over its monstrous head in the hope of dividing you in half. Adrenalin surges throughout your body, pain forgotten, energy fuels every fibre of your being as you dart to the left and lunge, your sword slicing through the coppery tang of the chamber's blood-soaked atmosphere. A loud, painful 'clang' assails your ears and the beast's axe smashes into the flagstone floor where you stood a heartbeat ago. Your legs drive you forward, your arms, shoulders and body all combine to drive your sword's cutting edge through the Guardian's torso, seemingly offering no resistance. The sword exits as you come to a halt, sword held in position of strike, your legs braced. Behind you a heavy crashing fills the chamber. You glance over your shoulder, and are amazed to see the Guardian's body cut in half, laying lifeless on the chamber's floor."

On the other hand, I've experienced this situation handled like so:

DM: "The Guardian attacks. What are you going to do?"

Player: "My character is going to attack."

DM: "Roll for initiative." (DM rolls their dice).

Player: (Rolls dice.)

DM: "Split initiative. You go first."

Player: (Rolls D20. Natural 20, the table erupts.)

DM: *sighs - rolls D20. Miss. "Ok, the monster swings at you and misses, you swing back and kill it. You've saved the party."

Personally, I tend to opt for the descriptive, cinematic style. Players want to feel the rush of excitement, feel the tension of their character's life hanging by a virtual thread - even more so when the rest of the party are down and that player is all that stands between utter failure or heroic success.

And let's be honest here, the whole aim in any rpg is to be heroic, whether you see yourself as an anti-hero, a people's champion, or an outright alter-ego of yourself, we all want to do something heroic once-in-a-blue moon. And saving the day tends to tick that box for most players.

CONCLUSION.

As a DM/GM you have a responsibility to entertain. Your role is that of Fate, the Narrator, the NPC, even the Gods themselves if required. You are not there to sound like you are announcing the train timetable at your local train station.
If your game feels dull and flat and lacking energy, it's down to you, the DM/GM. Don't blame the players. They feed off your energy, your imagination and input.

When doing the job well, players forget the DM/GM is there. Players are too far absorbed in the scene you are painting, and the life you are injecting into your game world. Time has no meaning. You know you've done your job well when player's actually groan and moan when you call time to end that evening's session.

The way a DM/GM handles the whole critical/fumble roll makes a massive difference. No player likes having their character fumble, but there are ways of handling it to soften the blow. Often humour is a great tool, especially if it's within a moment of tension. The idea is not to mock a player's character when they fumble, but rather to serve as a 'breather'. It's also a sneaky way for the DM/GM to 'disarm' a party's suspicion of what's to follow/lies ahead. In essence it causes a party/player to 'lower their guard'. 

Trust me when I say this, a sudden mood shift, and said party realising a world of hurt is about to descend upon them, has a greater effect. Eb and flow - that's what I'm talking about.

Having players on constant 'high alert' dulls the excitement and 'normalises' tension and danger, making for a less riveting and exciting gaming session. The same applies to crits and fumbles, played as highs and lows when the situation demands. Think of it as "high and low drama". Too much over-stimulation, just like under-stimulation, can be a recipe for role playing disaster.

Read the room. Gauge the mood of your players, keep notes on each player character's health, armour, magic and wealth (or lack of) - it will make your life easier and the flow smoother, especially when decisive moments occur where the lives of a player character or the entire party hang in the balance.

DM/GM your group as you would want as a player yourself. If that's a hard thing for you to do, or even imagine, then maybe your destiny lies on the other side of the screen.

As usual, I leave you with a musical gem. This time it's that brilliant tune from Boy George and Culture Club - "Do You Really Want To Hurt Me."  Until next time - enjoy.