D&D's attributes and saves are already a skill system. What are classically referred to as skill systems are just a means of arranging a set of extra probability modifiers for increasingly specific situations. At some point, most RPGs seemed to have absorbed three different ways of arranging probability modifiers or die-roll contextualizers: attributes, which I suppose are the 'ground level' way of describing an object mechanically and which are thus assumed to be ubiquitous in descriptions of slayable game objects*; skills, which are often a standardized list of genre-specific qualities which will be assumed to come up each once in a campaign, but which all operate simply enough that all you need is a name and string of numbers to describe. Then there's advantages and disadvantages, a set of opposed sub-descriptors which, because they often get nonstandarized paragraphs describing them which are expected to be memorized by the player, can be written on the character sheet in one line.**
D&D has been, in fact, kind of weird for not adhering entirely to this model, although it has all of these different kinds of modifiers or contextualizers already: attributes, attack bonus and saving throws (skills) and class abilities (advantages/disadvantages). When it got other things called skills and feats too one can reasonably look at the resulting kludge and start questioning which parts got used and which parts didn't. It's no wonder that those players which started thinking about RPG rules through D&D often split into the rationally-organized-rules camp (Rolemaster, HERO, GURPS) which try to keep everything but explain it all in a standardized way, and the slick-minimal-rules camp (OTE, Fate, GUMSHOE) which either keep it down to something you can count on your fingers, or at least only retain one category of modifier/contextualizer, or just quit the whole thing and go play a videogame.
*Leading to complicated rules for when they lack a modifier there, cf. 3e.
**Then there's also secondarily-derived stats, which are often used more than any other given skill. These are generally involved in combat, because every system after D&D needs combat to be a huge bloated system which rewards player knowledge of mechanical choices. Even Vampire, for some damn reason.
More Annwn Stuff
From the scratchpad:
• The Boar, usually resting, has been angered by pictish raids and is on the warpath. the picts plan to use the boar as a distraction; the band must deal with the boar and the picts at the same time.
• The secret of a terrible magical power lies with the soul of a man or witch tortured in the folds of the dragon-worm. only by consulting them while the dragon sleeps will they learn what they need and escape with their lives.
• The Raven-Giant, the great one, a shapeshifting druid in the form of a raven, whose head now guards Whitehill, where he watches over the assemblage of stolen wise-men's heads in the barrows.
• The bog-mummies in the swamps around the Great Tor have been whispering to the bishop there for many years.
• Cerridwen, the Bent One, is an ancient hag who dwells in her moving hut in the Otherworld.
• Characters do not level up with XP, but accrue magic power through finding magic artefacts, receiving boons, defeating monsters and stealing their power, or defeating mighty enemies and taking their heads. If they lose any of these things, they also lose the associated character powers.