[RPG] What effects do critical and fumble tables have on D&D 3.5


Just getting some extra damage, and just missing, seem pretty boring. A lot of people like to spruce things up by having critical hits and natural-1 fumbles result in a roll on a special table, which causes Fun™ to happen. But the Dungeon Master’s Guide warns that these increases randomness, and notes that this is bad for the PCs. Why? What effects do such houserules have on the game? In what circumstances are they a particularly good or particularly bad idea?

Best Answer

The Dungeon Master’s Guide is right to warn you about such houserules. The game was not designed for them in mind, and the game’s math reacts poorly to their introduction. In general, some of the biggest problems are that critical and fumble tables

  • Increase swinginess, which disproportionately punishes PCs because they see many more rolls than does the average NPC

  • Increase the importance of individual rolls, which disproportionately punishes classes that roll more often – notably warriors who have lots of attacks

  • Happen at random, which means they often prevent interesting things from happening more than they introduce new interesting things

  • Know nothing about what’s going on in the game – the characters, the plot, the strategies, the tactics – which means they cannot tie into the game’s truly interesting things

The first two problems are mathematical, and the first one, in particular, is rather difficult to overcome. These problems exist without regard for table, playstyle, or other preferences; no matter your group’s ideas of what makes the game fun, these are still issues that are worth consideration. Over time, the disproportionate punishment that they yield makes it difficult to keep a campaign going – after enough rolls, there will eventually be a show-stopper.

The second two problems are more conceptual. Because the tables are “ignorant” – of timing, of the other things going on in the plot – they are very limited in what they can actually accomplish. Even for a well-designed table, that works out some system to account for the mathematical problems above, still cannot help but be rather boring – after all, they are unaware of any of the interesting things in the game. They often disrupt the game, and rarely add to it. And, most likely long before you roll enough to end the campaign, you are likely to have a critical or fumble that is just nonsensical and, well, silly. Silly is fine for many campaigns, of course, but a good joke is all about the timing. The tables, by definition, don’t have that.

Thus, critical and fumble tables are bad for any campaign that either wants to last for more than a few sessions, or wants to try to be serious at any point. They work against both of those goals. Thus, the only kinds of campaigns where these problems are minimized are those that are both short, and intended to be silly. In other words, critical and fumble tables deserve approximately the same considerations as the deck of many things.

The problems in detail

Increased swinginess – disproportionately punishes PCs

Critical and fumble tables are a major source of “swinginess” – low-probability, high-consequence risks. Swinginess is, flat-out, bad for the PCs; that’s a mathematical fact, noted by the DMG. The reason is because a given PC simply rolls more dice, or has more dice rolled against him or her, than does any NPC.

Generally speaking, “Team PC” and “Team NPC” (to include non-character challenges as well) will see more-or-less the same number of rolls – when a PC rolls, it’s almost-always against an NPC, and when an NPC rolls, it’s almost-always against a PC. This keeps the numbers similar. But, there are many more NPCs than there are PCs, and more significantly, only a fraction of the NPCs are “important” – any given roll by or against “Team NPC” is far, far more likely to be targeting “Goblin #893” than it is to target “the BBEG.” Meanwhile, every single roll by or against Team PC is by or against someone important. Everyone on Team PC is important.

So Team NPC and Team PC are equally-likely to see a truly disastrous critical or fumble. But Team NPC’s disaster will probably befall some random mook. Team PC’s disaster will, by definition, befall a PC. So from the PCs’ perspective, they trade a mook for a PC – that is never a good trade.

There really is no way to “fix” this issue with a typical table; it’s too one-size-(doesn’t)-fit-all. It simply leads to making it that much more difficult for the PCs to accomplish anything. And the more severe the consequences from fumbles and criticals are, the more PCs have to invest in protecting themselves from it – which is investment away from things that will actually improve the story, move the plot, or accomplish goals. These are all bad for the game.

Mathematically, a conceivable solution would be to weight critical and fumble chances to compensate for the mooks. I.e. PCs only fumble X% of the time, and NPCs only critical X% of the time, where X is the fraction of “Team NPC” that is “important.” As should be immediately obvious, there can be no one-size-fits-all solution to this weighting, and almost as obvious, figuring out the weighting for any given campaign would be really hard. For mooks and the BBEG, it’s obvious that the former are unimportant while the latter is very important, but for NPCs between these two extremes it’s rather hard to say which side they fall on.

Increased impact of each roll – disproportionately punishes warriors

Typically, any given roll determines just success or failure, nothing more. How important that roll is depends on how important whatever you’re succeeding on is. For a warrior with four attacks, any one attack isn’t that big a deal – he’s got another three. For a mage, that saving throw roll is far more important – it’s the only roll he gets for that turn, it’s all-or-nothing.

But most fumble tables (I say most because it’s conceivable to design one that doesn’t; I’ve never actually seen such a thing, however) treat every roll equally. That means that characters that roll more dice – which is supposed to be a good thing, it means you have more chances for partial success and are therefore more reliable – get hurt much more than characters who roll fewer dice. This is a problem, because as it turns out, in 3.5 the characters who roll more dice are already the weakest classes. Warriors are far weaker than mages, and this rule punishes them more.

Worse, it punishes warriors for being good at what they do. The more attacks you make, the more chances you get for a fumble – the more chances you get to have a disaster. This is absolutely inexcusable; getting better should not make you more prone to disastrously screwing it up.

There are ways to fix this. Eliminating the chance of fumbles from iterative attacks works well enough (except that a fumble on the first attack often prevents you from even trying the remaining attacks, which screws things up again). Or perhaps giving a character with four attacks only a 25% chance to fumble where he otherwise would.

Worse: fumbles only for attacks

Some fumble tables are only for attacks (ok, let’s be honest – most fumble tables). That means that only warriors are at risk of them. This is, obviously, massively skewed, and in the wrong direction. I would literally refuse to play anything but a spellcaster under such rules, and I think you’d have to be particularly masochistic to do so yourself.

Fumbles for spellcasting require, basically, that you “fumble” when someone nat-20s (and confirms?) their saving throw against a spell. These fumbles should, perhaps, be different from what warriors see, but something similar. And then the spellcaster “crits” when someone nat-1s (and confirms?) their saving throw. I don’t think these are good ideas. I don’t recommend them. But if warriors have to do it, the mages sure better be, because the mages have too many advantages as it is.

Related issue: goblin dice

Basically, a d20 has a lot of variance. Twenty different possibilities, each one equally-likely. That works well when you roll dice a whole lot (e.g. in combat) but really poorly when you roll one or two “super-critical” dice (e.g. most skill use). By increasing the importance of each die in combat, you introduce some of the goblin dice problem into combat, the one place where (previously) the goblin dice worked. I strongly recommend reading @Magician’s blog post there; it’s really useful and valuable food for thought on the subject of dice rolls and what the math may mean for your game.

Context ignorant – boring failure

Because fumbles and criticals are, by definition, random, they are completely ignorant of context. They don’t happen “because” it would improve the game, they don’t happen “when” it would be interesting, they just happen. At random. Whether that is good for the game, or not.

This means that, since you’re rolling lots of dice and having lots of dice rolled against you, and occasionally those dice are crucially important, sooner or later you’ll have a fumble or critical that really disrupts the game, usually by getting a PC killed. How bad or not PC death is depends heavily on gameplay preferences, but I think all can agree that a PC who dies holding off the horde so the others can escape, in a last-ditch desperate attempt to stop the BBEG’s evil ritual, or otherwise dies doing something awesome, is the best-case scenario. Meanwhile, I think everyone agrees that, even if not “bad” per se, a PC dying to a random critical off of a mook in some random speed-bump encounter is a bit of a disappointment. We like the heroic sacrifice; the random death doesn’t really add much to the game. Deaths in between, where the PC just pushed too hard, got too “greedy” to finish off a target and put him- or herself at risk, or failed to account for some tactic or ambush the enemy had planned, are OK and an accepted risk of playing.

Note the big difference between the “best” deaths, the “OK” deaths, and the “disappointing” deaths. The best deaths and the OK deaths involve the player making choices that make their death more likely, either by choosing to sacrifice themselves or by simply making a series of mistakes in a deadly situation. The disappointing death just “happens,” a freak accident. No meaningful choice on the player’s part contributed to the death, excepting, perhaps, the choice to be an adventurer (read: play) in the first place. Critical and fumble tables dramatically increase the chances of “disappointing” PC deaths. And at the extreme, critical and fumble tables can turn Dungeons & Dragons into War Games.

Ultimately, we accept some risk of “disappointing” death in order to add some uncertainty to the game; knowing everything that’s going to happen before you do it takes the fun out of the game. But it’s a risk we have to consciously consider – the designers certainly had it strongly in mind when making the game. That’s why, in the DMG, they recommend against critical and fumble tables. Such tables upset the balance between having enough uncertainty to be fun, and keeping the risk of “disappointing” death low.

Finally, it’s worth mentioning a little more why “disappointing” death is disappointing; I’ve just asserted that, appealing to your emotional reaction to the idea. I imagine that most people are on board with that, but it deserves a little more discussion. Ultimately, we’re crafting a story when we play an RPG. The Player’s Handbook and Dungeon Master’s Guide go on at length about this. Random, “disappointing” deaths don’t add to the story; they halt it. They force the player to stop playing, waiting until either a new character can be introduced or the old character can be resurrected. The other players are forced to stop with the plot and either meet someone new, or else go off to resurrect their fallen comrade. If the story of how the PC died is interesting enough, this is fine – a break in the action, especially after a dramatic death, is appropriate. But if they were in the middle of trying to accomplish something, and the PC died randomly, that just disrupts the game.

All of this means that critical and fumble tables actually contribute to the problem of “boring failure” – particularly the fumbles. The whole point of a fumble table is to have something “interesting” happen instead of “just” an auto-miss – which is, certainly boring failure. But the fumbles aren’t actually interesting, they mostly just lead to more boring failure. Even if you don’t die, the fumble prevents you from doing what you were going to do. That’s boring failure. And fumbles are basically required to be boring failure, because of the following:

Limited benefit – don’t tie into any of the interesting parts of the game

What are the interesting things in the game? The plot, hopefully, and the characters, both PC and NPC. There are, hopefully, great heroes, dastardly villains, and an impressive scheme going on. And then there are the more mechanical bits – the strategies employed via classes, feats, and items, and the tactics in a given fight, the maneuvers used and spells cast.

Critical and fumble tables don’t interact with any of those things.

They’re random and drawn up ahead of time. They are, again, one-size-(doesn’t)-fits-all. By definition, they cannot be specific to the characters involved or the plot that’s going on. They don’t react to the particular strategies or tactics that are going on. They just are. They’ll be the same in every game.

The characters can react to them; that much is true. That can be interesting – sometimes. But they don’t just happen when they’re interesting. They just happen. At random. And that really limits their effectiveness as plot points – because they just don’t tie into the plot.

And the rest of the time, they are doomed to being boring failure because they just don’t have access to anything more interesting to interact with.

But I Don’t Play the Way You Do!

Of course; there are infinitely-many different ways to play an RPG, and we all have our own preferences. These get broadly lumped into categories, though it’s worth bearing in mind that truly, no two people are wholly alike.

That said, I maintain that the problems with critical and fumble tables are so severe, and their benefits are so minimal, that they are bad for your game no matter what you play preferences are. The only exception, already noted, is a short-running, silly game – for when you want to use D&D rules to play Paranoia. That’s a fine thing to do (though Paranoia itself has better rules for it), but for all other games, introducing critical and fumble tables will make that game worse, and, if they have already been introduced, removing them will improve it.

I will use the same categories as mxyzplk for this exercise; they’re not entirely ideal in my mind, but it makes it easier to directly compare the two answers.

Lawful Gamist

Mxyzplk paints a caricature here that I find obnoxious, and I have no idea what it has to do with “lawful” behavior, but nonetheless, if you are playing a game where the PCs are supposed to kill lots of foes and are not supposed to “lose,” then yes, we agree that critical and fumble tables are bad here.

Who I believe are being described here, and are thus being not-so-subtly insulted, are those who play the game more-or-less by the rules as written, and otherwise have a fairly legalistic relationship with the rules. People who expect the rules themselves to “work out” as they stand and judge rules by how well they hold up under scrutiny. Well, again, critical and fumble tables don’t stand up to much scrutiny at all They are clearly imbalanced, both between PCs vs. NPCs and between different classes. This, of course, has nothing to do with “winning” or “losing” but simply how effective these rules are at improving the game; they aren’t.

Lawful Narrativist

I think this group is, again, being caricatured unfairly – it could describe a much wider group than simply those playing with The Chosen One™. This describes any group whose idea of a fun D&D game is one in which the characters have goals, work to accomplish those goals, and hopefully, through much adversity, accomplish them. That could include The Chosen One™ but it also includes a far broader set of games. In fact, at a guess, most of them. Certainly in my experience.

Anyway, due to their random, context-and-plot-ignorant characteristics, critical and fumble tables add very little here. They do add disruptions that prevent things from happening. Since the goal here is for certain things to happen, that’s a bad thing.

Chaotic Narrativist

This group is contrasted with the “lawful” narrativists, in that they don’t come to the game with goals, but rather let those come out in play. I think that’s a false dichotomy, in that A. pretty much everyone has goals; any fleshed-out character should have something even if it’s just to bring in the harvest or get another pint, and B. pretty much every game should have events happening that change things, that add new goals or make older goals less important, unimportant, or even undesirable, by virtue of things happening in the game. I am extremely dubious of the claim that any game lacks either.

That said, for a preference, we could call the distinction between the two groups that the “lawful” side writes big, important, well-established, well-defined goals into their backstories, and that the player’s goal for the game is for the character’s goal(s) to be accomplished, while on the “chaotic” side you have less important and/or less defined goals, that can be thrown to the way-side as the game progresses and more important things come up.

I still say most characters are a mix of the two.

Anyway, if you want things to react to, things to come up that you can decide how your character will react... critical and fumble tables add very little to react to. They’re random and arbitrary. They have to be extremely minimal if they’re to be playable at all, but that means they aren’t really worth changing your world-view around.

But say something big does happen – that basically means someone died. The “chaotic narrativist” gets to react to his ally falling through the cruel whims of fate, hooray? Maybe for him, but it might suck for the player of the character who died. But we’ll stipulate that his player is also interested in how the party reacts. This is good, right? This is why we should have critical and fumble tables?

Wrong. Because they’re random and arbitrary. Because they don’t have timing, they don’t have awareness. They simply happen. And that means, after you’ve had this great moment where the character who hadn’t had real investment now wants to carry on his ally’s quest – or whatever his reaction to the death was – it happens again. And the second time just doesn’t mean as much. It waters down the effect of both.

D&D is a game overseen by a real, thinking, critical human being. The DM can, and should, push the PCs in ways that will intrigue the players, get their investment. The DM can, an d should, make calls that will give characters something to react to, and grow from. That is what the DM is for. The dice cannot replace the DM, and they do a really poor job of it. Considering all of the problems that exist with critical and fumble tables, the poor job that the dice do, the little that they have to offer, are just not worth the risks involved. The DM can do a better job without them.

Chaotic Gamist

Ah, here is our Paranoia game. At least, I assume that’s what mxyzplk is referring to, since he says they’ll appreciate critical and fumble tables. In a game of Paranoia (or a game of D&D emulating Paranoia), go ahead; that is a use-case for critical and fumble tables. I still say Paranoia, itself, is better for a Paranoia-style game.

But then he calls this game-style “gritty” and “hard mode.” Well, Paranoia’s not really that. Ah, so everything-stacked-against-the-PCs? Well, that can be accomplished far better without critical and fumble tables. Why? In this case, because of the inverse: NPCs fumbling, PCs critting and insta-killing, take away from the challenge. Per my first “problem” above, this is less likely than the PCs doing so, but it’s still a risk that’s just not necessary.

It’s not necessary because there are better ways of accomplishing a challenge. Harder, more intelligent enemies. Enemies in terrain and situations highly advantageous to them. And so on. “But wait! Why not have those things and critical and fumble tables?” Because you cannot have a no-holds-barred 3.5 challenge mode. There must be limits imposed by the DM; a DM going all-out can kill the PCs any number of ways with absolutely zero chance for the PCs to do anything about it. The DM can bring in demon lords, angelic forces, and actual gods. The DM can bring in Pun-pun, or any number of other absurd Theoretical Optimization tricks. For that matter, so can the PCs – they have to be limited somehow as well, or there is no challenge.

So you can’t just throw everything at the PCs. If you do, they’ll either die, or have to come to the table that, by strict RAW, can’t lose (and yes, there are a few of those). Critical and fumble tables are low-value distractions that detract from the PCs ability to face more interesting, more dangerous enemies. And risk eliminating an interesting challenge as collateral damage, robbing the players of a real challenge.


Again, critical and fumble tables are random. They are completely ignorant of what is going on in the game. And I have never seen one that didn’t have results that would be completely nonsensical in certain situations. There is a reason I said that a game with critical and fumble tables has to be silly – critical and fumble tables are.

How many fumble tables have you seen that includes you attacking yourself? Most do, that I have seen. Have you ever considered how you do that? Your attack damage involves a carefully-aimed swing, with all your might behind it. Body mechanics says you simply cannot get that kind of leverage in some swing that’s supposed to come back and hit you. Or are you accidentally flipping your sword around and stabbing it into your gut, seppuku-style?

Or how about the common fumble theme of attacking an ally? There are plenty of cases where that’s entirely possible, even likely such that a skilled warrior would have to be very careful, or avoid the blow altogether. Definitely. Except that your roll probably won’t come up “attack an ally” when that would actually be a risk. It will probably come up “you are shaken for one round” or something. Instead, you’ll get “attack an ally” when your ally is behind you and to the left, relative to where you were swinging at an enemy. How do you describe what you were doing where that was a conceivable risk?

These are just illustrative. Critical and fumble tables fail miserably for simulation, because they don’t simulate the current circumstances, they apply the same risks to every situation, equally. They might yield an appropriate result, but more likely they won’t, and sooner or later they’ll yield something truly immersion-breaking and nonsensical.

A simulationist approach might include special fumbles or special criticals, but not off a table – it should instead be determined by the DM and/or the group, whatever is realistic for the given situation. Then you avoid breaking the immersion by having a stupid roll come up.