Converting Vancian to Spell Point Casting?

[MaxiDuRaritry]

It would be pretty difficult to get simpler than "You can cast known spells by spending a number of points equal to the spell's level" and "Your 10th-level sorcerer has 35 points" while still using the same spells and spell lists.

If I'd added up every spell slot that same sorcerer would have gotten, I'd end up with more than twice as many points even before allowing for ability score bonuses. This would completely destroy any assumptions the spell designers might have made about how frequently any given spell would be used.

Maybe take a closer look at how psionic manifesters do things?

Their power costs are 1 power point for an unaugmented level 1 power, 3 pp for a level 2 power, 5 pp for a level 3 power, all the way up to 17 pp for a level 9 power. Note that those costs fall in line with the level at which you gain each new level of powers (level 3 for 2nd level powers, for instance).

The psion (sort of a mix of wizard and sorcerer in their general role and overall mechanics, but leaning more towards wizard) is here. Note that it gets 343 base power points at level 20, plus whatever bonus pp it gets for a high Int score. All power points from all sources are added to a single pool that can then be used for any and all purposes. Bonus pp are figured as: (key ability modifier × manifester level × 1/2) and added to the total.

That means a level 20 psion with a 30 Int (which is easily doable and relatively low) with no other sources of pp and no bonus MLs would have 343 + (10 × 20 × 1/2) = 443 pp, or a bit more than 22 manifestations at full augmentation (20 pp per each).

This seems like a lot, but I've noticed that a lot of players complain about running dry early. Since metapsionic feats usually cost additional power points, and most powers don't auto-scale like spells do (instead requiring extra pp be spent to bring them up to par), the whole system frequently requires regular rationing of power point resources to keep up. It's not terribly hard to do with the right power selections and proper use of other resources (such as skills, feats, and magic/psionic items, or just using powers that are strong despite not being fully augmented), but it does require some thought and effort, which seems about right.

Things are a lot tighter at lower MLs, of course.