I have a much-loved old D&D (2e) homebrew campaign world that some years back I translated into d20 terms. I was considering translating into M&M, but now I'm thinking that True20 will work even better.
Thing is, a lot of the flavor of the world depends on the distinction between wizards and sorcerers... and between arcane, divine, and psionic powers. I don't insist that the difference be the *same* as it was in d20, just that it be a real and flavorful difference.
I'm still working on priests and psions, but here's what I've come up with for sorcerers and wizards. Please let me know if you think they're balanced or not. (Note: The Wild Talent feat doesn't exist in this campaign.)
First, I'm thinking of requiring that Arcane adepts speak and gesture to use spells. There is a new feat, Reduced Ritual, that lets them overcome this need. (+1 to Fatigue DC for no speech, +1 for no gesturing, +2 for both.)
Second, note that Ward (and the new Dispel power from these boards) typically only work against one power source. ie, Dispel Arcane is not the same thing as Dispel Psionics. (And I don't think Divine power can be Dispelled or Warded at all.)
Third, arcane adepts can't use Imbue Life. Except for some variations on the sorcerer (the druid is one such - they're arcane, not divine, in this world), they can't use the Cure powers either.
Sorcerers must trade in their background favored feats for a supernatural power. (Yes, this means that ALL elves are potential sorcerers.) This power must be taken before any other sorcerous powers are; unlike the others, it uses total levels rather than adept levels for all purposes.
All powers use Cha.
Sorcerers do not take fatigue from powers. Instead, if they fail their save, the power goes out of control as per the Wild Talent feat: The caster is stunned and the power changes targets and parameters as the Narrator sees fit. A point of Conviction will prevent this from happening. (It may be spent after the save fails - the idea being that you almost lost control, but didn't.)
(The idea here is that sorcery is dangerous, but also easier to use in quick succession; they don't have to worry about mounting fatigue - though they *do* have to worry about being stunned.)
Note: Some sorcerers use music as part of their magic. Such cannot take the Reduced Ritual feat, but gain Fascinate as a favored feat.
Must be literate. (Literacy is *not* automatic in this campaign - you have to spend a language slot on it.) All powers use Int.
Wizards cannot spend a point of Conviction to gain temporary powers. Instead, they have the following ability:
Spell Preparation: A wizard may cast all but the last bit of a specific use of a power, and keep it held in abeyance until such time as he desires to use it. Any fatigue (and fatigue penalty) from the spell is suffered at the time it is prepared, not the time it is cast. When cast, the spell is treated as Quickened; it may be maintained normally. The maximum number of spells a wizard can have prepared is equal to his Int. Dispel and Ward work normally against prepared spells. (This might be a feat. But since I'm taking away their versatility-via-Conviction, maybe it should just come standard. I also thought about requiring a Conviction point to prepare a spell, but that didn't seem fair.)
Spell Trigger: A prepared spell can be set to go off as a reaction under certain conditions, without conscious volition of the mage. If the mage is conscious, he may prevent the spell from going off when the conditions are present, but this will cause it to be lost unless a point of Conviction is spent.
Transfer Spell: A wizard can give someone else a prepared spell to hold and use as they see fit; such a spell counts against the maximum number of spells the wizard can have memorized at a time. (Unless the other person is also a wizard, in which case they can "adopt" it as their own.) The original wizard may spend a point of Conviction to reclaim an as-yet unused spell (unless it was "adopted"); the spell is lost in the process.
Spell Trap (prereq: Spell Trigger and Transfer Spell):
The wizard may transfer a prepared spell to a person, place, or thing, set to go off when the right conditions are met. (This can make a handy geas! "Do it or else!" Though it can be beneficial, too.) Unwilling subjects can resist with a Will save against the wizard's power save DC. Dormant Spell Traps count against the number of spells the wizard can have prepared until they go off. (The wizard knows when this happens.) The original wizard can reclaim the Spell Trap if desired without spending Conviction.
"All right, I am not the Shadow. You have nothing at all to worry about. Except, oh, wait, I'm pointing a gun at you."