Whitebox20 has many magic systems. The “Traditional System” is based on having:
- a skill roll for the Tradition or School (Vivimancy or Healing or Illusion) to cast the spell correctly
- and a Channel Power skill roll that is used to make anything magic happen at all.
I like this, playtesters liked it, the first roll makes it dangerous, the second roll makes it positively nail-biting. Usually the spell selection comes straight off Wonder & Wickedness, plus some extra spells that players want.
First thing to notice: any character can cast spells, if they know any. And until you botch you can cast as much as you want.
Second: if you fail the first roll, it’s a botch, and you might want to run away. If you fail the second roll, nothing happens, but you can retry. And if you have mana to spend and you have a Caster perk/class/career, you can just spend mana and the spell is cast correctly instead. Fate/mana is used by all characters for all kind of things in W20, and Casters use it to get an edge with magic.
The only problem is that there are no easier or harder spells, for the time being, and that the high variance of the d20 makes simple negative check modifiers not doing what I want them to do. Because what I really want high level spells to do is:
- be better than simpler spells
- be riskier than simpler spells
- still be able to be cast by young, reckless and desperate wizards
Especially the last. So here’s the rule:
A character casting a spell of a higher level must spend an extra round casting the spell for each level of difference. During each of the extra rounds they must make an additional Tradition skill check. An equal number of Channel Power successful rolls are required: start rolling when the Tradition rolls are complete, and keep on rolling until a Channel Power roll is failed, and resume rolling the following round until the required amount of successes is achieved. The spell effects are
So, if a level 2 Caster wants to cast a level 4 Elementalism spell, they need to spend 3 rounds casting and roll 3 times on Elementalism, then roll 3 successes on Channel Power, taking as much time as they want.
Casters can spend one mana to fix a single Tradition roll plus a Channel Power roll per mana spent. If a Tradition roll is failed and not mitigated, the spell fails completely and all the failed Tradition rolls botches are independently resolved.
If the character stops or is forcibly interrupted, all the rolled Tradition tests are considered failures for botch purposes.
Since W20 characters grow over 3 or 6 levels (or not at all), if you’re using D&D spells use directly the spell level, not the minimum caster level: Fireball is level 3, so a level 3 character will not need to roll multiple Tradition checks.
Overcasting could be another option, but would require rigorous playtesting to avoid being too expoited: to cast a spell at a higher caster level (but the spell leve is not higher than the character level), specify a number of extra levels: the spell requires that many extra Channel Power successes in order to go off.