Over on Hot Air’s Green Room, Doctor Zero laments the late introduction of magic to Lost. He’s still hoping for a rational explanation for what’s happened so far, but he’s resigned to a non-rational explanation.

Early promises that nothing “supernatural” was occurring on the island drove the fans into a frenzy, as they pursued the grail of a science-fiction explanation for a series of fantastic events. The betrayal of this promise leaves us feeling like readers who reach the end of an intricate Hercule Poirot mystery, only to discover the killer was a vampire. It might have been a cool idea if the premise was explained in advance, but providing magic as the solution to a locked-door mystery is a cheat, and it’s bound to frustrate an audience which loves to piece together clues along with their heroes.

That’s a problem that fantasy games have with locked-room-style mysteries, but it’s not as bad as on television. Television magic has no rules. It’s best typified by the great Bewitched^•, because it was upfront about it. There were a couple of arbitrary rules about when magic could be used, but there was practically nothing magic could not perform. Darrin took a little heat for being paranoid at times, but he was right to be paranoid; his wife’s and his mother-in-law’s magic could do anything: make him feel what they wanted him to feel, see what they wanted him to see, and be what they wanted him to be. There was nothing in his mortal reality that they could not control or imitate.

Television magic does whatever the screenwriter or director wants it to do that episode. Mysteries are about piecing together the motive, the means, and the opportunity to the deed. In a world of television magic, the number of people with the means and opportunity is practically infinite. A good example of this is the Dresden Files series. While they generally did a good job of putting the restrictions on means up front—so that the viewer knew “this has to be black magic” or “there are only x kinds of people who could do this”—they generally stuck with piecing together the motive. If more than one person had a motive, Dresden had to pull a scam to get the perpetrator to reveal themselves.

That’s definitely one way of solving the problem. But in roleplaying games such as Gods & Monsters, magic isn’t at the whim of the writer and director. Magic has more specific rules. There are a limited number of specific spells, each with its own requirements. Sorcerors can research additional spells, but if they do they’re going to leave a trail of ingredients and calculations behind them. If you want to run mysteries, you need to stick to these rules.

For example, there are similarities to locked-room mysteries in The House of Lisport. The players know there is still treasure somewhere in that house. It’s the cliché that entices them to assist Meril. So where is it? Besides the people-related clues such as various diaries, there are also clues provided by the rules of magic. There has to be a means of opening the door. If the player characters are careful, the trigger will be pretty obvious. Go re-read the description of that room to see what I mean.

The spell itself must exist somewhere; it has to be in someone’s spellbook or scrolls. If it’s a generally useful spell, it’s probably been used in more than one place. If there’s a heart or trigger to the spell, that’s something that can be found. If it requires ingredients, then someone must have gathered those ingredients. If it’s a new spell of their own design, they must have conducted research, and that research is in their notebooks.

Rituals can do more things, but they also take more time and require more sacrifices. And they can only be done from specific locations.

Divine power is much less restricted—but prophets aren’t usually secretive, as that isn’t their purpose. If they are secretive, there’s a divine reason for it, and the gods are not often subtle.

It’s also a good idea to make sure the players are familiar with the rules of solving mysteries in role-playing games.