Rather than just lump this homebrew rambling in one giant posts I thought I'd pick and choose and give them each their own thread - once in a while, so hopefully I don't spam the place...
Spells! I do know there’s some rules now about spell schools, so what I’m about to talk about may be an inferior version of that. Basically, the idea here is to add some colour and variety to the spells used by players and NPCs. I’m one of the people who likes the AFF system because it’s simple, so this was an attempt to make spellcasting broader without making it any deeper.
Here’s the idea:Personalise Spell and Combine are no longer cast on the fly, but instead these are treated as the creation of a new spell. Customised spells can be learned, taught and created by NPCs and Heroes alike. But it’s not possible to personalise or combine already customised spells, only classic ones.
The spells listed in the rulebook are classic spells. They are the spells you learn studying in Salamonis or the Forest of Yore, for example, or get taught by a strict tutor your rich parents hired. This is reflected in their very direct names and lack of unnecessary effects – the Light spell makes Light, the Levitate spell makes things levitate. Very practical and utilitarian.
Any spell that was created by personalising a classic spell, or combining two classic spells, is a ‘weird’ spell. They usually have flashier effects that might intentionally disguise which of the classic spells it actually is, and a much more informal name, eg:
The Wailing Wall (Fog) 
The fog created by this spell appears to have ghostly faces floating in it, silently crying out.
Mighty Golden Hammer (Breach) 
Before impact, the target appears to be struck by a giant glowing golden hammer.
Mayal’s Gaze (See Through + Glowing Eyes) 
The caster’s eyes glow for the duration of the See Through effect.
The casting costs are worked out the same as it would be using Personalise Spell (+1) or Combine (+2). This means some custom spells are actually awful in terms of effect versus casting cost. Maybe that’s why those teachers disapprove so much?
The big advantage of this is variety in terms of magic, without having to work out and balance a whole new set of unique spells. It might even be that two identical weird spells have different names because more than one person had the same idea. Though I do make sure not to explicitly state the component spells of any spell that the heroes haven’t learned – it’s up to the players to recognise the effects and come to a conclusion on what exactly the spell is doing. Consider also that without seeing a demonstration first and passing a magic roll to recognise it they might end up paying a sackful of gold to Jorg to learn his 'Fearful Pitch' spell only to find out it’s just (Darkness + Fear), the same as the 'Night Terror' spell they already know...
There’s another advantage to me in that I get to come up with particular spells for my villains simply by combining or personalising a few classic spells, and coming up with interesting names for them. It keeps the players guessing at exactly what is being cast. If there’s a villain group, I’ll usually come up with one set of spells that they each use a few of. Sort of like how a militia may all use the same type of sword, all the mages in the ‘Cult of Wedling’ might use a handful of particular weird spells. Find a spellbook on one of them and now you know what spells the others might be throwing at you so you can prepare appropriately.
I also make sure to come up with some spells whenever there are neutral or friendly magic users in an adventure that have a suitable background. And of course, even though they’re weird spells, I still re-use a lot. After all they’re being taught like regular spells, so the more common ones will crop up often. Truly unique spells are still rare. For the heroes, it means spellcasters get their own version of finding that rare sword or magic shield, or fancy set of armour. In that maybe they find a scroll with a particularly potent weird spell. Or find a spellbook with a few spells they’ve never seen before. Or find a travelling mage who will teach them an interesting spell if they [insert quest here!] for him first.
I’ve got the cost of creating a new weird spell, and the time it takes, to be three times the same as if the heroes were learning the resultant spell - and they have to know any spells that they’re combining. This hasn’t been tested yet since nobody has yet got around to wanting to make their own spells, so I can’t say if it’s too high or low. It may be easier to rule out spell creation for heroes entirely, as something that takes “years of experimentation” or the like - which is something I considered and could go either way on. But the idea is it would take a lot of experimentation and effort to come up with something new, and so encourage the heroes to seek out new spells and leave the spell tinkering to people that want to stay at home all day messing with magical energies.
As for lore, these weird spells would be frowned upon by the more classically trained and uptight, since it isn’t the ‘correct’ way of casting those spells. On the other hand casting classical spells out in the wild might make others who know magic think you’re a bit of an academic who isn’t used to the rough life. They’re also less fancy looking, so may be less likely to impress the locals. So the spells starting Heroes and NPCs know depend on their background. For example, if a hero was taught magic by their uncle who ran away from home to start a magic curiosity shop, their spellbook might have more custom spells than classic ones. Or a barbarian hero might know several spells unique to his tribe and related to their particular culture with not a classic spell in sight. A student fresh out of Salamonis, nothing but classic spells.
Anyway, that’s the idea I’ve been running with. Using Combine and Personalise to create custom spells to add flavour and variety to casting without having to come up with unique spell effects and somehow balance that with casting costs and durations and suchlike. Then using this to create unique 'loot' and pools of spells for various factions and backgrounds. If I share any adventures with weird spell lists in them, at least now you'll know what that's about even if you don't agree.