Removing Ability Scores

I got an interesting comment on my recent post In Defense of D&D Stats in Simple Language: What Measure is an 18?, and I think it merits discussion before we change topics:

Out of curiosity, I wonder what your opinion of the ability score themselves is. I haven’t had an opportunity to explore the versions before 3e either, but lately I’ve been considering how the ability scores are implemented…they allow for some interaction in the game (ability score damage, partial upgrades), but since almost everything depends on the modifier couldn’t the scores themselves be removed entirely?

I see two questions here: how do we use ability scores (rather than modifiers)? And, can we switch over to modifiers entirely? For the most complete answer I’m capable of providing, we have to do it for 3E (and by extension Pathfinder), 4E and 5E.

From what I can remember we use ability scores in the following ways:

Ability score damage. In 3E monsters can deal damage directly to ability scores. This is why “what happens when you’re at Strength 0” is relevant, because there’s a chance a wraith could whittle you down to immobility. 4E doesn’t have such a thing, and I’m not aware of a monster that does it in 5E. Ability damage is one of the reasons I like using software (or at least a character sheet in Excel) to handle 3E and Pathfinder campaigns, because properly-built software can detect a change in an ability score and change all the relevant numbers.

Can we use modifiers? Probably. All we need to do is halve a monster’s ability score damage, and we can use modifiers with no problem. Decreasing a modifier of +3 by 1d2 is no different from decreasing a score of 16 by 1d4. The only difference is for odd numbers. A character with Strength 13 who takes 1d4 Strength damage loses an average of 1 Strength modifier (because there’s only a 1/4 change of rolling a 4 and dropping to a 9 [-1 modifier], and a 1/4 change of rolling a 1 and dropping to a 12 [+1]) instead of 1.5, the average of 1d2. I have actually seen characters who put an extra point into certain scores as an ability damage buffer.*

Spellcasting levels. In 3E a caster needs an ability score equal to 10 + spell level to cast a given spell. A sorcerer with Charisma 18 can cast 8th-level spells, but not 9th. 4E doesn’t have spells levels and 5e has them but ability scores aren’t particularly relevant to casting.

Can we use modifiers? Yes. We can easily say “you need a modifier of 10 + half spell level to cast a spell”.

Feat prerequisites. Every edition has feats, and every edition uses odd ability stores as prerequisites. As I understand it this is explicitly to make off ability scores matter more. A fighter with Strength 12 hits just as often for just as much damage as a fighter with Strength 13, but the latter can get Power Attack and the former can’t. Odd ability scores unlock certain additional abilities that mean the increase to an odd number is mandatory for certain builds.

Can we use modifiers? Yes. If we don’t have odd ability scores, we don’t need a mechanic specifically designed to allow them. Just use the modifier (if you’re feeling generous) or the modifier plus one (if you’re not) instead.

Bits and bobs. This covers narrow cases like carrying capacity, rounds a character can hold their breath, etc. They’re not really a big deal but they need to be said.

Can we use modifiers? Yes. The only thing we need to change is the reference. For example, for carrying capacity in 3E, remove the odd-numbered lines from the carrying capacity table. In 4E and 5E, create a table or equation that relates modifiers to weight (+1 is 120 pounds, +2 is 140 pounds, etc.) For holding breath, just say “You can hold your breath for ten rounds plus two rounds times your Constitution modifier”. It’s a little more math but it’s nothing complicated.

Point buy. 3E and 5E have options for allocating stats at character creation, and 4E assumes you’re using point buy and only suggests rolling as a tertiary option. With point buy odd ability scores are worth more than lower even scores, but not as much as even scores are worth more than lower odd scores. For example, it may only cost one point to raise your 12 to a 13, but two points to go o a 14, then two to a 15, three to a 16, etc.

Can we use modifiers? Yes, but. We can remove the point buy options for odd scores and only use the values for even scores, connecting them to modifiers. This may create some weirdness in point allocation because of how the scores are balanced. In Pathfinder, only two even scores requires an odd number of points, 14 (five) and 18 (seventeen). So if your point buy is using an odd number of points, you must have at least one 14 or 18 (or you discard points at the end, which means you’re not as powerful as you could be, which means the party’s stats may not be even, which discards one of the primary reasons for using point buy at all). We’re taking a system designed for choice, removing some of that choice, and hoping players are willing to do the arithmetic calisthenics they need to make everything work with additional restrictions.

Partial upgrades. Some epic destinies in 4E and prestige classes (and monster classes, I suppose) in 3E give a +2 bonus to an ability score. Every other permanent bonus to an ability score is a +1.

Can we use modifiers? Not so much. There are two ways we can go about this. One is to track the half-increases in some other way. Perhaps we allow a half-modifier, so a character’s Strength is actually +1.5, or we track whether an ability score is “primed” so we know a future increase will change the modifier. But that’s exactly what ability scores do. We’ve eliminated a mechanic just to put in back in place in a way the rules don’t like. So that’s out.

The other option is to change how we do ability score increases, sometimes drastically. Increases like those from magic tomes have an obvious solution: disallow the odd options. The increases from leveling are rougher. 3E gives +1 bonus to an ability score at every fourth level. We can change that to a +1 bonus to the modifier every eight levels, so players lose a potential score increase, or every six levels, so they gain one instead. 5E’s ability score increases change by class, so we may have to tweak each class individually. Maybe fighters gain an ability modifier increase every four levels, and they can instead gain two feats, though providing this sort of sudden benefit changes the pacing of the game. It also means characters who gain an odd number of ability score increases must have a feat whether they want one or not, and we need to either hard-code the level where they gain a feat or trust players to figure it out themselves. In general, any rule that includes “also, remember how you leveled six months ago” is a bad rule. A character sheet should work without permanent memory.

4E is an even bigger problem. It gives a +1 bonus to two scores at levels that end in 4 or 8 and a +1 bonus to all scores at levels that end in a 1 except level 1 (it’s so easy!). We can’t just say “Gain a +1 modifier instead” because that breaks the tightly-constrained ability score rules. And we can’t say “increase one modifier by +1, which cannot be the same modifier you increased four levels ago” because of the same memory problem as before.

We can change it to “add +1 to two ability modifiers at levels that end in 6”. Compressing the L11 and L21 increase doesn’t work the same way because the tier transitions need that very intentional change. We could say “add +1 to three ability modifiers at levels that end in 1” as long as we’re fine with players putting those increases into the same stats both times, because that’s how players work. There’s not a huge difference between a maximum ability score of 30 and a score of 32, so long as we’re fine with going outside the 4E barriers.

So, can we remove ability scores and use modifiers exclusively? Sure. But we’ve skipped the first question we should ask whenever we’re thinking of house-ruling something: why?

What do we get from removing ability scores and using modifiers exclusively? We save some room on character sheets. We more easily define 10 (now +0) as the baseline with other values above or below it.

What do we lose? We now have a drastically higher cognitive load for any place the rules use ability scores. We have to consider our custom damage changes, custom lookup tables, custom equations, and custom feat and leveling mechanics, none of which the rules mention in any way. It’s fine for players who can do that on the fly but a pain for players for whom the rules are too ingrained or new players who have to deal with house rules before they can get used to the rules in the first place. Even the room we save on character sheets is wasted unless we design our own sheets that use that space for something else.

We can pitch ability scores without breaking D&D wide open. But should we? I’m not convinced. If you’re trying to get into D&D from Apocalypse World or something similar go right ahead, but it’s not for everyone.

* — I’m going to preemptively defend this sort of player. Yes, having an odd ability score as an ability damage buffer is a type of metagaming. But it’s also a way of defining a character. As in, “Rock Hardslab is so strong! He can even take a hit from a wraith and barrel on, unharmed, where lesser action heroes might falter!” I could have a whole other post someday on how selling something the right way can be the difference between rejection and applause.