Feats:
Spend 2 energy for +3 to a skill before you roll it.
Anyone can spend 1 energy to add +1 to a failed skill roll.
Pick a Homeland [where you grew up], a Craft [that you practiced as a child, like gathering flowers or repairing leather] and an... I'm not sure. There should be a third, though. List these on your sheet. You get a +2 bonus to tasks involving them.
I also like the idea of there being 3 spells per art... like Necromancy could cover Spirits, Death (and the likelihood thereof) and Reanimation. These all use the same skill? Or when you take that Art you get those three skills at +1 each? (alternately, you can take 1 at +3 or 1 at +2 plus 1 at +1 instead of all three at +1).
Spells: Trivial (+2), Minor (+0), Major (-4), Dramatic (-10).
Necromancy: speaking with dead spirits.
Trivial: sensing how much death there has been in an area or the presence of undead, making bones stir spookily, appraising the chance of a wound or infection turning fatal.
Minor: seeing ghosts and other spirits, reanimating a smaller-than-mouse-sized insect shell, determining how many deaths someone or something has caused over the years.
Major: banishing a spirit, reanimating a mouse or rat-sized creature, speaking with a present spirit.
Dramatic: binding a spirit into your service, reanimating a larger creature, summoning a particular spirit that is not present and conversing with it.
Try a 24hr design day? Devote the whole day to writing up the game?
Spell casting is stat (Magic) + skill + 2d6 vs difficulty.
For every point that you fall short, you must spend 1 MP to get the spell off. If you refuse, then the spell fails and you take 1 damage from straining yourself (possibly one fatigue instead). Thus, the better you are, the more magic you can throw around without suffering drain.
Everyone starts with 6 HP and 6 MP, modified by race. When you "gain a level", you add +1 to both and have 3 skills go up by +1 each. Instead of improving skills, you can buy one new Feat instead. Hm. Maybe HP and MP should be treated like special skills and you only improve them if you feel like it? Dunno... it kind of fits a D&D-like fantasy setting for PCs to get better at surviving regardless. Hm.
Feats/spells eat up MP. Combat Feats often say something like spend 1 MP to do X. MP might well represent willpower or enthusiasm instead of magic. Say Motivation Points.
Beating the target number by 5 is a crit, double effect. Beating it by 10 is a double-crit, quadruple effect.
Spells are Feats that have their own skills and each has a list of trivial (7), minor (10), major (15) and dramatic (20) spell effects. Some feats open up advanced spells by adding new types of effects that you can use, like Lightning instead of Fire.
Let's see... if taking a spell gives you that skill at +1 and the typical race had a Magic ranging from 1 (wild rat) to 6 (royal mouse). Let's say that +2 is typical for a stat.
So now a starting mage might have Magic +2 and know Spark at +1. That gives them an average result of 10.
Okay, with a base roll of 2-12, average 7... difficulty 5 is so easy that with a +3 bonus you never fail. 10 succeeds on average with a +3. 15 is only possible on double-sixes with a +3. 20 is impossible without a further +5 bonus.
MP comes back quickly, so that folks who rest up after a fight are quickly able to do it again. Perhaps 1 hour of rest restores all MP? Or 10 minutes of rest restores 1 MP?
A common fighting feat lets you Lick Your Wounds and restore HP to yourself at a cost of MP.
The Medicine skill lets you attempt to restore damage (1 point) on someone. Only usable once, then their wounds are bound. Crits heal 2/4, naturally.
The base difficulty for a skill check is 10. Rolling a 5 or less in total is a botch.
Snake-eyes is an auto-botch unless you spend 1 MP. Double-sixes is treated as a 15 instead of a 12 if you spend 1 MP.
Magical healing is very slow and takes awhile to kick in (perhaps the effects work overnight?). Or it turns wounds to fatigue so that you can then rest them off overnight?
Too Small to Hit: when attacked by an oversized creature, you can spend 2 MP to reduce their success level by one (to failure at worst) by diving aside at the last second.
Fail a skill check by exactly 1: spend 1 MP to turn it into a success.