We are using a version of scalable spells for RMFRP. Spells are easier to cast, but only certain spells are scalable.
For all intents and purposes, "caster level" is "Ranks in List". The knowledge you have in a single List is specific to that set of spells. Casting "at Rank", we also eliminated overcasting. You only know the List up to the Ranks in that List.
When you cast a spell that has a "/level" increase, you only get the 1st lvl increment. Casting Earthen Spikes is an 8th lvl spell, requires 8 PP and has a duration of 10 min/lvl. In our game, the duration is 10 min. That's all you get for your 8 PP! Each additional 1 PP gives you another 10 minutes. Duration now reads: 10 min +(10 min/+PP).
So any spell that has a "X/lvl" is a scalable spell.
The benefits to this system are that low lvl Professions can have a decent chance of actually using their spells because they cast at Rank. Everyone is more successful at casting spells, but not everyone can power the same kinds of effect. The high lvl Fighter who picks up a Rank in a List, doesn't get his "character lvl" to fall back on. He still has to spend the PP if he wants the "/lvl" AoE, Duration, Range, etc of the spell. As we know, most Fighters don't have a surplus of PP.
Modifications to the SCSM Chart:Power Points: +1 SCSM/PP >minimum to cast.
(You get a
slight bonus to cast by spending the extra PP for /lvl increase.) This has saved our 7th lvl Monk's life, twice. Only applies to spells that are scalable.
If Spell Failure: -1/PP > minimum to cast. The bonus PP acts as a neg on the Spell Failure Table. You couldn't control the power....
This way, we have some spells that are scalable and everyone can cast a bit easier. Not many people are going to spend precious PP on long durations, extra range, etc. But if you really want it, then you can make it happen.
I also dropped PP multipliers. The key is to make PP more valuable than Mithral to the PCs. I do have PP Adders; there are just a few spell Lists that make these. +3, +5, +10.. You can have more than one but you have to Attune to it. Each additional adder is a DR harder to attune. Spell Adders reset each dawn.
The beauty of Spell Mastery...
Spell Mastery saves PP! My players have learned to develop Spell Mastery to save their precious PP; doubling the Duration of 10min/lvl to 20 min/lvl on the Earthen Spikes above means that 8PP gives you 20 min and each additional PP gives you 20 min.
Magical Languages (One Language /Spell List is how I run it.) and Ritual Magic can also give similar results. The players embraced it. Our Mage took up Drumming to increase his Ritual Magic and learned Magical Languages for the PP heavy scalable Lists.