The more I think about both of these ideas, the more I like them. The former gets rid of classes, gives (a little) magic to the masses, and helps further eliminate the idea of dump-stats (without taking the 5e route of giving some classes Charisma-based attack rolls). The latter, in addition to making weapon choices more interesting, gets rid of the Base Attack Bonus...
This last bit personally interests me. BAB is a static value. It is a statistic that does not involve any level of choice -- or rather, it is rolled up in your choice of class(es). By getting rid of it and effectively making attack rolls into skill checks, we have one less random number from which we have to derive other values, AND one less remnant of the class-based system.
So, there is one other static value or class-based value that the game fundamentally dependent on that might be reasonable to convert into a trained skill...
Pathfinder (and D&D 3.x and the d20-system in general) uses three saving throw values: Fortitude, Reflex, and Willpower. These correspond to three of the six ability scores, and, arguably, give greater weight of importance to those three stats. They also, like BAB, advance only based on your choice of class(es).
The extant editions of D&D that have followed 3.x both tried to mitigate / get rid of the effects of these values in different ways. 5th edition made them ability checks, for all six ability scores, as a way to a spread out the value of the various stats (thus reducing the sense of "useless" ability scores). 4th edition made them truly static, much like a character's Armor Class, as a way of reducing the number of rolls made in combat. But nobody liked that. The saving throw roll is too intrinsic to D&D's sense of risk.
But what if we used the exact same approach to Saves that we do to Weapons? What if, instead of a saving throw that advanced statically by class, saves were a skill that you had to choose to improve, or not.
The big pluses with this are that: (a) You eliminate the class-bound static values, and (b) You add yet another element of variability between characters and choice for the players.
The obvious con is that you have to spend skill points on them. If they come from your main pool of skills, then the saving throws water down the potential skill levels of the character, by increasing the number of things he must spend points on. With weapons, we created a second pool, because there are so many. We could do that with saves, and have a pool of "Saving Throw Skill Points", but even with a 5th-edition approach of one save per stat we have only six skills to choose from -- which would quickly make the characters relatively uniform.
So what if we make Saving Throws into actual skill checks? Some might be obvious: Perception check to see through an illusion? Acrobatics check to leap out of the way of a fireball?
Of course, this would require either on-the-fly DM interpretation (or player arguments) of what skills are or are not appropriate for resisting a specific spell. Or highly complicated replacements of the "saving throw" field in every spell description to detail which skill check(s) to make. With the THOUSANDS of spells available for Pathfinder, either of these would be a nightmare.
So, we need a clear 1-to-1 relationship of Skill to Save category, but we don't want those skills to only cover the saves, since that overly waters down what a character can learn to do.
So, 3 skills...
The "Reflex save" is fairly easy to replicate with a skill. The aforementioned Acrobatics skill just makes sense here. It is already a fairly broad skill, having been expanded in Pathfinder to encompass in totality three different skills from D&D 3.x (Balancing, Jumping, and Tumbling), which together encompass roughly 99% of how players and DMs describe Reflex saves occurring. It just makes sense to replace Reflex saves with Acrobatics skill checks.
Of course, this puts A LOT of value on the Acrobatics skill, since it already encompasses so much that an adventurer might want to do.
"Willpower saves" are harder. There is no single, broadly encompassing skill that would cover all the ways you might fight through a mental attack -- Perception for Illusions, Sense Motive for Divination, any of a number of Knowledge skills, Spellcraft?
However, if you look just slightly outside the core Pathfinder skill set, there is one skill that fits the bill pretty well. The Autohypnosis skill (from Psionics Unleashed by Dreamscarred Press) is traditionally reserved for Psionic campaigns (and, indeed, existed in the D&D 3.x psionics rules as well), but covers such things as Resisting Fear, Memorizing long strings of text, and clinging to life while bleeding out. Using Autohyposis in place of Willpower saves makes sense, and attaches a number of useful (if slightly esoteric) functions to our "Willpower skill".
Perhaps not nearly as universally useful as Acrobatics, but sufficiently useful outside of avoiding spells to make it a worthwhile skill purchase.
This is the real toughie. For starters, "Fortitude saves" are traditionally based on Constitution and Pathfinder has no Constitution-based skills. Likewise, the only Strength-based skills are Climbing and Swimming, which are highly specific. Autohypnosis encompasses some Fortitude-like functions (resisting poison), but has already been claimed for Willpower....
So what do we do?!
Well, it turns out that there are a lot of things in Pathfinder that call for random Constitution checks -- running, forced marches, holding one's breath, resisting starvation or thirst, etc. Pathfinder's solution to allow some characters to get better at these kind of things is a feat: Endurance, which gives a bonus on checks of this kind.
Now, all of these checks have always bothered me as a DM -- mostly because its a lot of random things to remember. Fort save vs. exposure (but Endurance applies), Swim check to resist exhaustion (but Endurance applies), Con checks here and there (but not centrally documented, other than in the Endurance feat. They are a pain to remember and even the best DMs tend to forget to call for them.
Well, it turns out that all of this was solved in the edition-that-shall-not-be-named (4e D&D).
|Look at that! An Endurance SKILL...|
Poof! Not only do we have a skill that covers all that random shit from 3.x/Pathfinder, but we also have the perfect stand-in for a Fortitude save skill, with universally broad usefulness for adventuring types.