Vancian Magic is the depiction of magic found in Jack Vance's The Dying Earth stories, rather rich and arcane version of Rule Magic. Vance's books were a big influence on Dungeons & Dragons, which in turn influenced most every RPG since. As a result, a number of Roleplaying Games feature Functional Magic that has more in common with Vance than with real-world occult theory (or the sort of magic that appears in TV and movies). Even some games that deviate very far from D&D's other paradigms in other areas still subscribe to Vancian magical theory (example: the Sorcery system in Amber DRPG).
Vancian magic is defined by a few key traits:
- Each magic spell does exactly one thing, you generally can't improvise a new effect.
- Spells must be prepared in advance. Wizards can prepare only a fixed number of spells, and can use each one only once before having to prepare it again. Spells are like magical ammunition, and you have to reload.
The individual spells have names, which are often colorful and sometimes mnemonic or alliterative. The names also often credit the creator of the spell, being the magical equivalent of eponymous naming structures in science, like "Hawking Radiation" or "Lorentz Equations".
Game and Story Use
- One benefit of using Vancian Magic is that it provides an easy way for the GM to step up character power levels bit by bit, by providing access to scrolls or spellbooks that include new spells. This broadens the options for the character, without necessarily boosting the sheer day-to-day power level. They become more generally useful, but not always more potent.
- The major hurdle the vancian wizard must overcome is how to predict which spells will be useful in the near future. You may find yourself in a situation where a seemingly trivial spell in your repertoire would work wonders, but because it's a minor or very situational spell, you didn't prepare it.
- Another hurdle is the idea that you can't just repeat the same spell freely. You can end up in situations where you've got plenty of power left, but can't use it for the type of spell that would be most helpful right now. You already fired the armor-piercing bullet, so to speak, and all the other ammo you're carrying is useless now.
- These issues are often compounded by the Squishy Wizard and Linear Warriors Quadratic Wizards tropes.
- This system sucks vigurously when used to model any kind of channelling (e.g. priests channeling divine power) or any kind of shamanistic magic.
- The fixed effects of most vancian spells, together with the relentless combat obsession of most RPGs also lead to the jarring illogicality of the wizard, specialising in fire magic, who couldn't light his pipe without levelling the tavern (or using a match like a mundane). This is the Ur example of vancian inflexibility and is usually (partially) patched by many systems but the underlying problem remains.
- For a slightly more flexible magic system, see Spell Points. For much more flexible systems, see Improvisational Magic. In general, see Laws of Magic.
- Some fun could be had in scenario design by using the limitations of the Vancian system concept, especially that each spell does one thing and can't be dialed up or down. Just take care that you balance things such that "complications" are still "fun". If you spend too much time making the PCs best powers not work, you'll only frustrate the players.
- The PCs need to magically kick in the doors, but the only spell you have access to will level the whole castle (which is inconvenient because of the hostages inside, or something along those lines). Once the hostages are freed, though, you can blast the place.
- You need to break a curse, but the only spell that will do so will also ruin all magic items within a 10-mile radius. A trip to the wilderness is in order.
- An act of diplomacy (or getting a business deal to go through) is trivially easy as long as you're willing to rob the other party of all semblance of free will. You can be Master or Slave, but no where in between.
- Some environmental effect is easily dealt with as long as there's advance warning enough to prep a few castings for it. But that means delays, and time is growing short.
- A horrible blob monster can be easily defeated with a minor cantrip whose usual purpose would just be to knead bread dough without getting your hands dirty. For once those 0-level spells pay off!