Bounded Accuracy vs. Simulation

For over 40 years D&D has had an issue with the to-hit system. At first, they had giant AC versus level tables for each class; then they switched to a system where different classes had different to-hit bonuses at maximum level, and they metered out the to-hit increases every level. It meant if you weren't a pure fighter, forget hitting anything at maximum level because all the monsters at max level were balanced for a fighter's attack bonus.

D&D 3 and Pathfinder follow the sort of design theme of great classes (fighters) get +20 at max level, sucky classes (rogues, clerics) get +15 at max level, and really sucky classes (mages) get a +10 at max level. Mind you, if you are fighting an AC 30 monster, great classes will hit at 50% of the time, sucky 25%, and really sucky will be like "5%, why even try?" Of course, mages will be flinging spells, so that 5% never really matters. Feats and proficiency make the difference, and one had to take into account damage output, but the base system is still set in an assumption of some classes are better than others when hitting a target. There is also a multiple attacks thing here with high attack bonuses, so damage output is linked in.

D&D 4 sets everything on a sliding scale, using 1/2 your level plus your ability score DRM to give you your attack bonus. You must have a high ability score, maintain it, and have the recommended magic items for your level to "keep up with the Joneses," aka the monsters. If a monster was 4 or more levels above you, forget it. If a monster was 4 levels below you, you could care less about them. It was a very MMO feeling game that was balanced "on the levels" and had a flat balance.

D&D 5 preserves the flat MMO-style balance, and puts everyone on the same to-hit chart, but makes the maximum bonus a +6 for everybody. Everything else, monsters, magic items, and combat, has been realigned to fit within this new model. This is called "bounded accuracy" and it is the central design premise behind the new D&D, to get those numbers back in control and make everyone feel they can contribute. There are plenty of problems with this, such as the lowest-level monsters being able to hit high-level heroes (in the context of this system), and high-level heroes still having a high miss rate that still feel unsatisfying for many. The system also breaks with mass attacks and does not scale well with larger groups or attacks that add conditions on hit (poison).

Then again, it feels like they have been wrestling with making the abstract AC and level-based to-hit system for 40 years and they still haven't got it right.

Abstract Accuracy

It is difficult to criticize the D&D to-hit system because it is intentionally abstract. You can get into a long argument with other players and fans of differing editions, and all you will be doing is arguing over is if mauve or thistle is more "purple." Because the system is so abstract, the designers need to carefully "code" AC and attack bonuses in with each edition to make the game work. In computer programming speak, D&D's combat system is spaghetti code and a mess of special cases, and it needs to be hand-tuned any time they move to a new edition or they make a new expansion or book for the game. The AC and to-hit numbers have to be directly balanced against the monsters from level 1 to 20, or everything breaks down.

In D&D 4, it did not feel like the later levels were as well-playtested, and things felt like they broke down the higher level you went. There were so many erratas and rules changes over the life of that game it spun your head, along with a second version of the monster manual coming out in Essentials that changed the math again. Every monster manual changed the math, and it hurt the experience for us.

Simulation Games

Contrast this with a more simulation based game with a less abstract system. If my fighter has a 60% chance to hit with a sword, it doesn't matter if I am swinging it at a level 1 goblin or a level 30 dragon, I am still making that piece of metal strike that other shape no matter what that other shape may be, 60% of the time. The effects of what happens will vary greatly upon what I hit and the personal power I have, If I am as strong as a hill giant I will expect to splatter the goblin and hurt the dragon. If I am as strong as a human, I expect the goblin to take a wound, and the dragon to laugh and say he didn't even feel it.

Most of the time. Exceptions and great rolls always exist.

You can give a rogue and a fighter the same to-hit, and work out the differences with powers, techniques, and ability scores. You can do away with abstract levels and subjective armor class values entirely. You can rate armor on protection, and let the dice fall where they may because you created a simulation system where things in your world work a certain way.

Your characters exist within themselves, not in the context of a carefully balanced level system.

Level Systems

Now, level systems are great because they let you change the math and put out a new edition. The only exception was AD&D 2nd Edition, where they cleaned up the original AD&D rules and improved the presentation greatly. They really didn't change the math, but they streamlined it and created the "I don't understand why nobody gets this" THAC0 system, but I guess many had a problem with it. THAC0 (to hit armor class zero) was easy enough to understand, but they should have made AC increasing and flipped those around, and just said to-hit is your base plus target AC, like they did in 3rd Edition.

Negative AC in AD&D sucked, and it was likely nobody ever thought ACs lower than zero were ever needed. Explaining negative AC felt like explaining THAC0 to the uninitiated.

But part of the problem with an abstract system is linking level to to-hit, especially when it starts blowing out your dice range. Having a +20 to hit at 20th level, plus ability DRMs, plus magic item bonuses, plus feat modifiers, plus situational modifiers can get you to a final to-hit bonus of +30 or more easily. On a 1-20 scale, a +30 makes the entire number range of your randomizer meaningless. You are rolling between 31 and 50, and trying to hit an AC of 42.

The mind boggles, the numbers are so high, and the DC and AC numbers are again on that meaningless, super-high if +10 is better than give me another +20 MMO number scale that never ends.

Bounded Accuracy is the New Coke

I am not convinced D&D 5's bounded accuracy does much to solve the problem of D&D's abstract system other than change the numbers again. There were some D&D and Pathfinder mods (E6 most notably) which put a level cap of 6 on the game, and this appears to be where the bounded accuracy idea originated from. E6 is a laudable game modification for D&D 3.5 or Pathfinder, it assumes that 6th level characters are the most powerful in the game world and lets the monsters past that be the world's "boss creatures" and teamwork is needed for beating them.

You throw out the entire upper three-quarters of the game to do so, but it does get that sense of scale and challenge back that D&D loses when a thief levels past the power of an adult red dragon. Where D&D 5 and E6 differ is that in E6 there is a huge world out there more powerful than any single hero could ever be. In D&D 5, every hero can be a level 20 monster some day, yet they still need level 30 monsters out there that are even more powerful than that.

But limiting everyone to the same to-hit chart and capping it at +6 (plus mods)? Really, none of my players really like advancing that slow, and it feels like a grind. Your hit-points go up normally, so you have these hundreds of hit point monster characters walking around with a +3 or a +4 to-hit, and your sense of heroic scale is all skewered. I would prefer the level cap to six to a slow grind to twenty and a +6 when I get there.

Yes, bounded accuracy makes the numbers meaningful again, no question.

But I feel you give up too much. High level characters lose their sense of "being good" and the harsh d20 and its variability stomp all over a modifier range that starts at a +5% to-hit bonus and ends up at a +30% to-hit bonus for epic characters. Even with ability score mods and magic items it doesn't go much higher, and high level characters feel like they are just talented normals. It feels like you are just fooling with the numbers again instead of fixing the problem.

Wonderland

It all feels like D&D's power curve has been messed up since the original box set that level capped you at three, yet the monster lists had 9 or so hit die dragons. Sooner or later, you could level past those dragons, and we entered a strange fantasy land where we needed bigger and bigger challenges to overcome. D&D has always had this "videogame in pen and paper" feeling to me, where of course characters are entitled to incredible amounts of hit points and power, and the sense of scale between normal people and high level characters reaches absurd levels.

D&D 5, despite bounded accuracy, I feel does not address this problem, as the higher levels in that game still entitle characters to massive amounts of hit points and damage output that boggles the mind compared to a first level character. The difference between high-level and low level has not changed, only the dicing model has gotten flatter and everyone can hit each other now.

It still feels like a videogame to me. I feel that a dragon like Smaug out of the Hobbit is beyond the power of any single hero in that world, and any hero could ever be. In D&D and Pathfinder, this isn't the case. I get this World of Warcraft feeling where characters are driven primarily by advancement than story, and personal power is the name of the game. It isn't down, it doesn't feel realistic, and the abstract system keeps you from ever understanding or balancing it because it is so carefully tuned and system-wide teeter-tottering on the sum balance of its parts.

If you disagree with two-handed weapon damage and change it, you break the rest of the game.

Abstractionification

It isn't D&D or Pathfinder that is at fault, I feel, it is the abstraction and the magnitude. Once you abstract one piece, you have to abstract everything, and then the balancing act begins. Level based to-hits and ACs that could mean everything from a high dodge to tank armor along with out-of-control hit points and damage make the entire system feel more like an ever-higher level Facebook game requiring more time and clicks than something that models reality.

If there was a D&D game out there that got it right in terms of comparative power and the weak against the impossible, I would be all over it.

I want games that make me fear the dragon, not know that someday I will out level it. I want games that give me a basis in reality, rather than hand wave it away and apply an arbitrary number to it. This is likely a personal preference thing with me and my players, and I try my best at explaining it, so don't feel bad or get angry if you enjoy these games. These are systems that within their own spheres, work, and they are tuned to work well.

But they don't feel real, they feel like videogames.

But a character with 200 hit points when a normal person has 5? I lose it. I can't relate. That number is meaningless in reality, and really only has a place in electronic gaming to me. Same thing with wildly high to-hits, damage outputs, or world-ending spells. It is an unrelatable world-crushing Superman to the common-man Batman.

It is having it all versus being a hero without.