For what itâs worth, my simple approach is: defiling allows you to cast spells without consuming spell slots; instead, you destroy plant life around you in a radius similar to that described in the original & updated AD&D settings books. The radius from which you can draw power increases as a function of your highest available spell level (at the moment Iâm going with 2x), so that you can potentially defile to cast 2â3 of your highest level spells before you run out of available plant life (thus sacrificing your ability to cast lesser spells).
There are a few reasons for this fairly simplistic approach:
1. Any Spellcaster can Defile
Defiler vs. Preserver shouldnât be an option chosen during character creation or at 2nd/3rd level, etc. The preservers donât learn a different type of magicâthey simply exercise a level of self-control and caution that defilers typically do not.
2. Preservers Can Fall, Defilers Can Be Saved
It should always be possible for a preserver to fall to defiling, and for a defiler to find redemption. Using different classes or preset items such as a faster spell-level progression makes it difficult to move between defiling and preserving, making these types of character evolution difficult if not impossible to perform.
3. Defiling Must Be Tempting
Getting a re-roll on an existing spell as in 4e isnât tempting. The faster level progression of 2e is moderately tempting, but isnât a thing in 5e, and falls foul of rule 2 above (e.g. a level 10 preserver becomes a defilerâdo they retcon their abilities? Gain new spell levels?). In 3e, defiling lengthens the casting time of a spell in return for a +1 bonus to caster level. While helpful, this isnât tempting except in quite particular circumstances (if I was a level higher, Iâd do 6d6 damage instead of 5d6).
4. Defiling is the âEasy Routeâ to Power
To match the idea that defiling is the lazy option, it shouldnât take more effort, it should take less. That rules out the 3e mechanic of increasing spell casting time. If we take the 2e revised rulebookâs idea of wizards fetching and storing their power at dawn, then defiling would be drawing energy at the time the spell is cast, true. But that shouldnât take a noticeable amount of extra time: the defiler isnât being careful, theyâre reaching down, grabbing, and pulling with all their might, paying little attention to the amount theyâre gathering. Itâs a quick, almost reflexive actionâthey open their palm to the ground and cast the spell, acting as a conduit between the ground and the spell effect. The fact that they can do it quickly is a benefit of defiling, making it more tempting.
4.5. Preserving Should Be Careful and Methodical
As a corollary to rule 4, it might be worth saying that preservers need do take additional time to cast their spells, as they are consciously monitoring the power theyâre drawing as a discrete mental task.
- If we were to include this rule (Iâm still on the fence here) then it might open up another ruleâanyone with no spell slots can cast spells by drawing from the ground (if there is available plant life), but preservers doing so need to take at least a bonus action to do so. For example, maybe a preserver can cast spells to level n. Without using a spell slot, they can use a bonus action to draw power for any spell up to level n-4. For anything else, they need to use a full standard action to draw power.
5. Defiling Draws Attention
A friend of mine played a Templar in a 4e game, and used arcane defiling in the middle of Urik. That character drew a lot of attention. The sorcerer-kings donât tolerate other defilers, and will hunt them down. This means that over-using the great powers given by the no-spell-slots rule for defilers will certainly land them in trouble; players will have to be careful to choose the right time for using this ability.
Overall, these rules have rather worked out well. My main intention was to make preservers really think hard about the defiling option, and Iâve seen that happen. Iâve seen characters grow by developing conflicts between preservers and defilers on the same team. One spellcaster takes care to arrange their spell slots for an upcoming battle, and another just throws out high-level spells one after the other, bam-bam-bam. Itâs fantastic to see.