|An ideal use for your PolyHero Wizard Dice!|
When I first got into Savage Worlds, one of the things I liked most about it was that it doesn't generally require a lot of bookkeeping. One of the major exceptions was Power Points, which are something I never really liked.
There are a few "No Power Point" rule variants out there (such as the ones in SWD and Hellfrost), but the system is clearly designed with Power Points in mind, and many of the individual powers were very obviously balanced around their Power Point cost. So even though I dislike Power Points, I still end up reluctantly using them.
However, I'd like to propose an alternative solution.
One of the more interesting mechanics from The Black Hack is the "usage die"; each time you use a consumable item, you roll its usage die, and on a roll of 1-2 that die is reduced by one die step, so a torch might be reduced from d6 to d4, or a quiver of arrows might be reduced from a d10 to a d8. The same concept could easily be extended to the powers in Savage Worlds, except using the PP cost instead of a fixed usage value of 1-2.
The Power Die
Instead of expending and tracking individual Power Points, spellcasters just have a single "Power Die" sitting on the table in front of them. Immediately after casting a spell, they must roll their Power Die, and if they roll equal or lower than the PP cost, their Power Die is reduced by one die step. If this takes them below d4, they lose their Power Die, and cannot cast any more spells.
The Power Die would also be used for maintaining powers, for activating any Edges that have a PP cost, and so on.
If the PP cost of a power exceeds the number of sides on the Power Die, the caster cannot even attempt to cast the spell. Note that the Power Die is not a trait die; it does not Ace, you don't roll a Wild Die with it, and you cannot reroll it with a Benny.
Example: You have a Power Die of d8, and want to cast a spell with a PP cost of 3, so you roll your Power Die. On a result of 1-3, your Power Die would drop to a d6, otherwise it would remain at d8.
Every hour, you roll your Power Die, and on a 1 your die increases by +1 die step, until it is fully recharged. If you no longer have a Power Die, you should use a d2 for your recovery roll instead.
Rapid Recharge (and Improved Rapid Recharge) allow you to roll to recover every 30 (or 15) minutes.
Calculating the Power Die
Most Arcane Backgrounds start with 10 PP, which would be the equivalent of a d6 Power Die. Every time they take the Power Points Edge, their Power Die should increase by +1 die step, to a maximum of d12.
Mathematically speaking, on average a Power Die of d4 would be the equivalent of 4 Power Points, d6 would be the equivalent of (4+6) 10 Power Points, d8 would be (4+6+8) 18 Power Points, d10 would be (4+6+8+10) 28 Power Points, and d12 would be (4+6+8+10+12) 40 Power Points.
This obviously doesn't scale in quite the same way as the standard Power Point rules, however I don't think it's too bad when you factor in the risk element of the Power Die - it might provide more fuel for your spells on average, but it's not as reliable, making it more difficult to plan out a spellcasting strategy.