Bag o' Nifties: Tricks for GMs

The Double Check - Running Dangerous, Unpredictable Magic

by Dan Pond
March 7, 2002

The Problem

Yeah yeah, I know I said this article was going to be about Nifty Teleportation Tricks, but other priorities have emerged since then. Last time, I outlined a few ideas for attaching a price tag to elemental magic, but what people where really looking for was a way to make magic dangerous and unpredictable, not dangerous and costly. As luck would have it, I've got just such a nifty squirreled away in the vast storehouse I call Dan's Many Works In-Progress. So, here's a sneak peak...

The Solution: Double Check

This system defines spellbinding as a contest of wills between magus and magic. Each use of magic (whether it be a spell, power, or talisman) requires two actions, usually made as opposed checks. The first, called a "Power Check," is based on the potency of the magic being summoned. The second, called a "Control Check," is against the spellcaster's relevant skill (see below). This "double check" has four possible outcomes:

Both Checks Succeed: The spell is bound and goes off as intended. All is right with the world.

Both Checks Fail: The spell unravels and nothing happens. The summoned power is insufficient for the full desired effect, and what power there is does not get channeled appropriately. Fizzzzzle.

Power Check Fails, Control Check Succeeds: You've Underpowered the spell. The magus did everything right, but there's just not enough mojo to get exactly what they want. Instead, the effect is only partial, the duration is limited, the effect "fades" in and out, or any other limitation you can devise.

Power Check Succeeds, Control Check Fails: You've got an Overpower on your hands. The magus has summoned more juice than they can control, so the magic does what it wants. Overpower effects could include obviously magical light shows, dangerously amplified spell effects, uncontrollable durations, accidental targeting of bystanders, or pretty much any other fiendish faux pas you can dream up. (This is a big excuse to be an evil GM, so make the most of it!)

The Double Check is pretty much system-neutral, so you can slap it on any game that requires magi to make some kind of spellcasting skill check. Just assign spells/effects target numbers of their own, based on their power level; the higher the rating, the more likely it is to Overpower. You should give subtle effects (illusions, divination, etc.) lower ratings because Underpowered effects are still pretty appropriate outcomes for them (vague visions, flickering illusions, etc).

For Control checks, spellslingers can use any skill appropriate to the desired spell effect. Most of the time, this will be something like "wizardry" or "fortune telling," but combat-related magic could use a character's "martial arts" or "ass kicking" skill, and a clairvoyant could use their "investigation" skill. Note that having a low-level spellcasting skill doesn't make a character less able to cast spells, just less able to control them. In other words, powerful magic isn't harder to cast, it's just harder to control. In a way, it's actually easier to cast! When you play with fire, prepare to get burned.

Playtested Examples for Your Perusal

Here are a few magics I've used in playtest games, along with some of the Under- and Overpower effects that came with them:

Visions - The character who had this stock clairvoyance power was an unabashed Miss Cleo rip-off. She thought of a question she wanted answered, then used tarot cards or a trance (her "fortune telling" skill) to summon a vision. If it Underpowered, she'd only get vague information, the vision would end prematurely, or the information would be misleading. On an Overpower, the vision would take over and keep her entranced for hours, turn into a horrific nightmare, end with mind-splitting pain, or make her temporarily absorb a personality trait from someone in the vision.

Pyrokinesis - This interesting character was an arsonist given magical control over flame, but only for non-destructive effects. (He has to stick to benign applications like light, protection, and cleansing.) Underpowered effects pretty much just left him high and dry: partial protection, dim light, etc. If he Overpowered while trying to do something questionably destructive, the magic would "punish" him by starting everything on fire, or backlash against him and inflict hideous burns... as reminders for the future.

Shackles of Spirit - This binding ritual was used to gain control over magical creatures. Underpowered effects would only bind a creature for short periods of time, would leave it able to attack the caster (at a penalty), or would give it enough vestigial free will to interpret commands in ways that sabotaged the magus' goals. Overpowered bindings might broadcast the magus' activities to all nearby magical beings, or leave the bound creature so little free will that it was essentially mindless, capable of following instructions only in the most literal sense.

A Note on LARPs

As implemented above, the Double Check requires a GM to determine the specifics of Under- and Overpowered spells. In a live-action game, a GM might not always be available. So, I'll propose a system for handling dangerous magic in a LARP. This is an absolutely untested idea coming straight out of my arse, so please take it with a mountain of salt.

When describing each magic power in the game, include at least two Underpower effects and two Overpower effects. When one of these unfortunate events occur, let the would-be target pick from the appropriate list. This gives the magic a genuine, goal-oriented point-of-view that's (usually) in opposition to the caster... which is especially apt for Overpower effects. If the target is unaware of the casting, the selection should be made either randomly or by a GM. Since the effect has to come from a pre-determined list, magi can make sure nothing too egregious happens to them, while still having the specifics stay out of their control.

Next Time: Tips for faster gameplay & cinematic action!

All Worldz: A Game of Interdimensional Civilization by ImEG Games