The next logical Trappery would be a fantasy setting example, but here we start running into complications.
What I've been doing so far could mostly be summed up as "de-abstracting" traps into something that has a bigger presence in the game than a couple of rolls. Once you're looking at fantastical settings, though, some new factors and assumptions come into play. These are:
- Sufficiently advanced technology
- "It's not magic, it's INSERT-THINLY-DISGUISED-WORD-FOR-'MAGIC'."
What does magic mean for traps?
Both magic and hypertech (and potentially some high-end current tech) introduce new possibilities into the game. Ultimately, they're quite likely to lead to having more traps, and more powerful traps, than are plausible in a real-world setting. The exact details will depend on how the game treats magic.
don't know who you are or and what you do or and where you go when you're not around...
Forget fireballs and summoning demons for a minute. The first and probably most important possibility magic presents is discrimination. Magic can not only function as a trigger for traps, but identify all kinds of information about an intruder. Things like weight, height, species, alignment, religion, membership of an organisation, general intentions, blood type, complete genetic makeup or simply "identity" are grist to magic's mill. This means a trapper can create traps that are far, far more discriminating about triggering, and massively reduce the chance of a false positive.
As I've mentioned before, false positives are one of the major checks on the lethality or general unpleasantness of traps, and on their placement. People are very unhappy about working near dangerous traps, or even very painful but non-damaging ones. There's also the simple inconvenience of getting trapped for a few hours or having work come to a halt while some trap is cleaned up and reset. With near-zero false positives, though, these checks are removed.
Practically speaking, this will result in more traps because they can now be placed in high-traffic locations, in the Dark Lord's bedroom, and other sensitive places without much downside - and since traps have a lot of advantages as protection, it's a natural thing to do. It will also result in more powerful traps because the trapper isn't concerned about becoming a trappee, or about catching a loved one or sue-happy visitor by mistake.
'til the end of time
Another significant feature of magic is its longevity. Legend and fantasy fiction alike often present magic as everlasting, lingering even while creators and physical surroundings fall to dust. If this is the case in your setting, then magical traps will remain a threat longer than just about anything else. The clockwork guards and scything blades may be rusted to nothing, the crossbows' bowstings may have rotted long ago, the lake of mercury have evaporated and the poisons have turned into harmless dirt, but the curses and glyphs of day-ruining will still be around to make Nebraskie's life thoroughly miserable. From a GM's point of view, this offers a way for abandoned places to still have defences and present dangerous problems. It also, of course, allows magic-specialists to use some of their skills during an exploration.
Everything louder than everything else
The third change magic introduces is just how bloody weird your traps can get. There are, fundamentally, limits to what mechanical traps can achieve. Magic, on the other hand, can turn someone into a squirrel, detect their romantic preferences, conjure up another squirrel to meet those preferences, compel them to fall in love, teleport them to the Plane of Nuts and Birdfeeders, trap them both in a bubble of accelerated time while they raise an extended squirrel family, record the whole process on a crystal ball protected by impregnable wards, teleport them back, transform them back into their original form, and then threaten to send the recording to their parents, spouse and selected national media organisations.
Magic allows you to influence intruders' behaviour through enchantment or mind-altering substances. It allows you to use living creatures without worrying about keeping them alive in the meantime. It allows you to teleport intruders elsewhere - like right out of the tomb and into a nearby volcano, or a city gaol. It allows you to turn them to stone until the next patrol visits, or forever. It allows you to wipe their memories, or implant new ones. To induce horrific hallucinations, or send messages. To blind, deafen or paralyse. It can summon guards, and even teleport them in.
I can't think of a suitable Meat Loaf quote
Finally, magic is - at least potentially - invisible. It's just there. Unlike a trick flagstone, tripwire or big pit full of spikes, there's not necessarily anything to show that there's a spell waiting for intruders. This point needs careful consideration, because it risks leaving traps as the arbitrary die-rolling exercises that caused all this writing in the first place. A related point is that magical traps could end up as a problem exclusively for wizards - which isn't necessarily an improvement on being a problem exclusively for thieves.
When using traps in a magical game, it's a good idea to consider how you actually want magic to work. This will relate to how it works elsewhere in the game, so some of your work may be already done. Broadly speaking, I think there are two poles to the approaches, which I'll call esoteric and mechanistic.
Esoteric magic is not readily analysable. Spells are discrete and somewhat arbitrary things, entities in their own right. You can't probe the composition of a spell or expect it to combine with others in systematic ways. This is likely to work better in systems with limited magic and a fairly broad-brush, narrative approach to what it does. In this approach, a magical trap is likely to be a single spell that exists for that purpose. It will have one or more set countermeasures, so overcoming the trap is a matter of knowing those countermeasures, which may be entirely arbitrary, intuitive, or involve a terrible pun.
Example: Surloc's Bonecage
The Wizard of Saffron Waldren, fed up of apple-scrumpers, turns to his arcane talents. Drawing runes left-handed with powdered amber, incanting the names of the Nine Winds in reverse alphabetical order, and ritually burning a pillow and two Granny Smiths picked before dawn on a Tuesday, he invokes the dread power of Surloc's Bonecage to protect his orchard. The children of the neighbourhood are flummoxed. However, old Nanny Quiggin (who used to do part-time witching in Douglas) happens to know that you can break the spell by spilling the blood of a penguin not more than three foot tall over the runes, then walking backwards through the warded area wearing shoes on your hands and singing "One Man Went To Mow" until you lose your voice. As it happens, you can also break it rather faster by casting Tarah's Hungry Hound.
Mechanistic magic is basically something you can break down and analyse in a semi-logical and semi-consistent way. This is probably going to work better in a system with a fair amount of magic and reasonably detailed explanations of what it does. In this approach, a magical trap would be either a) a single spell that's designed for exactly that purpose; or b) a number of spells (and possibly mechanical components) combined into something that works as a trap. So a trap might involve a spell that detects intruders, a spell that sends water pouring across the floor, and a spell that sends 100,000 volts through said water a few seconds later. I would expect the latter to be relatively more common, and increasingly so as a system becomes more mechanistic in its approach (for example, a game where magic consists not of specific spells but of pools of abilities, and the important factor is the caster's mastery of each pool).
The mechanistic approach would tend to treat wizards like hackers or mechanics. They can analyse a spell into its component parts, and work out ways to take out part of the system, rendering it ineffective. They might even be able to take control of a trap, or change its parameters to trap someone else. This approach will treat magic-hacking a bit like combat: it will involve several rolls that go towards the goal.
Example: The Honey Trap
Lady Windemere, irritated by the plebs who keep wandering through her estate, decides to set a trap near the gates. Her Head Witch needs to combine several spells into a workable trap. A watchful eye detects trespassers, and can recognise members of the household to let them past. Once a trespasser has been found, instant excavator digs a large pit under them, while sweet summoning covers them with a lavish helping of honey. Finally, a simple attract insects draws the attention of twenty nearby beehives.
Anyone wishing to avoid the trap can target any or all of these spells. Removing the excavator would make it much easier to escape the bees, while cancelling the attract would leave them simply sticky rather than stung. They could remove summoning, which reduces the bees' incentive but still leaves them hanging around. Of course, the eye is the best target, but it may be harder to dispel. A blind spell would take care of the eye, a repel insects would counter the attract, a fill pit or raise hummock would counter the excavator, but there's no specific counter for sweet summoning. Of course, they could also turn invisible, impersonate Lady Windermere, or simply put up an umbrella to avoid the honey and then scramble out of the pit ASAP.
Of course, many traps are not purely magical, but include physical components as well. These allow much more scope for non-casters to use their skills.