"You can ride without a saddle, Lord?" he asked me. "Without a horse, tonight, if necessary."
--Excalibur, by Bernard Cornwell
In my recent post on the latest playtest packet, I wrote about skills and proficiencies a lot. I thought about it some more, and now I want to recapitulate and, for my own benefit as well as clarity in analysis, reorganize the information. The thing is, the rules as presented are misleading, though I don't blame the designers - this is a playtest packet, and their final-form information presentation should wait until things are finalized. This is the implementation of a plan Mearls alluded to in multiple Legends & Lore posts, particularly here and here.
The game has eighteen things it describes as skills, each of which is lightly attached to one ability score.
Animal Handling (Wis)
Sense Motive (Wis)
Sleight of Hand (Dex)
Okay, cool. But what about the tasks that don't slot neatly into these skills, like opening locks, disarming traps, riding a horse (okay, Animal Handling isn't a terrible idea there), donning a convincing disguise (okay, sure, you could use Deception)... and so on? Can you be unusually good at resisting fatigue, toxins, or suffocation? Of course you can - but what 4e called "the Endurance skill," D&D Next calls "proficiency in Constitution saving throws."
To cover the range of things characters can currently be proficient in, we also have to consider the various kinds of tools. The tools each contain their own subsystem of rules, and we can all be glad that this isn't the final published work, because as information presentation goes, it's a nightmare. The short version is that proficiency with a toolset lets you apply your proficiency bonus to skill checks that incorporate that toolset; it's not really clear what kinds of tasks require tools, though. If you wanted to climb a sheer rock face, do you need proficiency in Athletics (the presumptive successor of the 3.x Climb skill - at least, it certainly was in 4e), proficiency in a climber's kit, or both in order to apply your proficiency bonus (or, if you have both, do you double your bonus)?
There are eleven tool proficiencies, which may or may not be implicitly connected to an ability score:
Artisan's Tools (with a DM's-discretion crafting system; no ability score noted)
Climber's Kit (Str)
Disguise Kit (Cha)
Gaming Set (no ability score noted)
Healer's Kit (Wis; has a meaningful application even for non-proficient characters)
Herbalism Kit (no ability score listed; includes both an implied DM's-discretion crafting system and an explicit crafting system)
Horse (no ability score noted; presumably Dex)
Musical Instrument (presumably Cha)
Navigator's Tools (Wis)
Poisoner's Kit (no ability score noted; includes both an implied crafting system and an explicit crafting system)
Thieves' Tools (Dex; the system information for disarming traps and opening locks is stored here)
What I'm getting at here is that the game's definition of "a skill" is arbitrary and misleading. What they need to mean when they talk about "having a skill" is "a task or set of tasks for which you gain your proficiency bonus." Some of these tasks implicitly require some sort of device, implement, or entity beyond the character - such as needing a horse in order to ride (as subverted in the quote at the top of this page), or needing tools in order to pick a lock (picking a lock without tools is usually set to a Nearly Impossible DC). This also means that every rogue can pick locks and disarm traps, but core functionality like Stealth is... a newbie mistake waiting to happen, I guess.
We're not quite done, though. There's also saving throw proficiency, since a Dexterity saving throw covers the tasks that 3.x handled with Escape Artist and Balance check, and Concentration is probably split between Constitution and Wisdom (except that, well, they got rid of spell interruption). Saving throw proficiency only comes from classes at present. While I certainly think it would be a terrible idea for Backgrounds to hand out more saving throw proficiencies, it seems to me that Intelligence and Charisma saving throws barely have any use anyway, while Dexterity, Constitution, and Wisdom are exactly as all-important as you'd expect.
The tool proficiencies are at odds with the loose-and-open nature of skills. The tool list describes specific, narrow tasks, while the DM Guidelines and How to Play documents describe a very loose system in which DMs determine which skill to use, which ability score to use it with, and any necessary DCs. Now, anyone who has ever compared a module to the core rulebooks knows that published material habitually ignores listed DCs for traps, locks, and other tasks, but even so, D&D kind of needs to decide on an approach and stick with it. On the other hand, absolutely any time the stakes are high (such as restoring hit points with a Heal or Medicine skill), the rules should go for clarity rather than open interpretation, because high stakes plus open interpretation means lots of time-consuming arguments.
Also, though I've mentioned this before, I think it's ridiculous to have a Medicine skill that doesn't help with hit point recovery beyond stabilizing the wounded. If a character is going to spend one of her precious few skill proficiencies on Medicine, maybe it could do something useful. As it is, it is not necessary to use a Healer's Kit, doesn't improve a Healer's Kit, and requires either the Cleric class or the Loremaster feat; the Healer feat doesn't so much as reference the Medicine skill.
As for the skill list, they need to get rid of this concept of "tool proficiencies," and simply list "skills that require a tool kit for their basic function." They want to keep the list short, though, and I appreciate that, but the current list is twenty-nine (41 if you count each artisan tool kit separately; God help you if you count each musical instrument and gaming set separately) skills with enough skin cream or whatever that they look like they're eighteen.
So let's go back to those tools and see which ones justify their existence as freestanding skills. Let's change them to gerunds while we're at it, so they will fit in with their new friends in the skill list. Artisan Tools? Sure, I want there to be a crafting system, so let's include a Crafting skill. Obviously I don't think that an alchemist should automatically also be a gifted blacksmith, so let's carve out some design space for specialties, while we're at it. A Climber's Kit is just a tool to improve an Athletics function, so it doesn't need an independent skill. A Disguise Kit, likewise, is a function of Deception in the current rules, though recent G+ conversations have worked on unraveling that notion - not that I know where you'd put it instead. I don't hate the idea of Disguise as an independent skill that can, situationally, also grant Diplomacy bonuses through intelligent, culturally-appropriate application of makeup.
A Gaming Set? Sure, okay, Gambling could be a skill, though I'd rather fold those into a Streetwise skill instead, since there's currently only a Charisma check with no applicable skill if you want to gather rumors in a town or city. Healer's Kit - well, Medicine, obviously. Herbalist's Kit: Crafting is abundantly obvious, but there's a good argument to be made for Medicine here too, or Nature, or Arcana. Giving all three skills unique applications for an Herbalist's Kit sounds like a good time to me; for that matter, let's get Religion in on the act with frankincense and myrrh.
Being trained in Mounts or Horses is just Moon Language: a person with any respect for gerunds learns Riding. The rulebook and the character sheet should reflect this idea, especially given how aggressively the design wants to be newbie-friendly. Musical Instruments make no secret of the fact that they are a subset of Performance. Navigator's Tools likewise call out that players roll Survival to use them. The Poisoner's Kit is really a specialized form of an Herbalist's Kit, and as such could be a Crafting specialty, or Nature, or Thievery, or even Religion in some settings.
Thieves' Tools are useful enough that they should be their own skill. If 4e was for you, then Thievery is a pretty solid choice for the name. If not, how about Breaking & Entering, Disable Device, Disable Security, or Skullduggery? The breadth of a Thievery skill should be commensurate with other skills that are a particular class's go-to skill for most tasks, such as Arcana for mages, Religion for clerics, Nature for druids, and Performance for bards. Sure, rogues already have Sneak as a pre-eminent option, but... anyway. Not the point. Thievery could readily cover a wide range of interactions with fantastical devices (intersecting with both Dungeoneering and Engineering), or poison use as mentioned, or interfacing with the criminal underworld (yeah, Streetwise is better for this).
In conclusion, the various proficiencies of D&D Next are a strange set of choices, even given the reasoning Mearls has presented. I'm confident that they'll change before the actual release. If they don't, well, character sheets and metagame syntactical constructions will just linger in unnecessary awkwardness for the lifespan of the edition (sort of like this sentence).