Missing trap triggers by chance
What would you guys consider a reasonable way to handle the random circumstance that a PC just... doesn't set off a trap? I don't mean they pass a Perception (incidentally, does "hard" sound about right for the perception check needed to spot a trap for which you are not specifically looking?) or Detect trap check and deliberately avoiding it, I mean just failing to set the trap off by complete blind luck. Like, by some complete fluke of chance they manage to step over the tripwire, or fail to step on the specific tile needed to set it off? I initially thought a D20 roll by the GM might work, roll 10 or less and the trap goes off, allowing for positive modifiers like Physical Prowess, and maybe the trigger needs some kind of minimum weight, which the character might not meet. Is this even necessary, or is it getting a bit too granular? If it came up, my plan would be, as the GM, to just roll without telling the players why - if they never set off a trap they don't even need to know it's there.
Avoiding damage from traps
OK... so, having determined that your character HAS set off the trap, I've collected the various traps from the Rifts Game Master's Guide, and I'd like to see if anyone has suggestions on how a character might avoid taking damage from these types of trap. I think a simple dodge roll might work just fine, but it'd be useful to see if anyone has any alternate suggestions, or maybe some kind of penalty:
- Pit traps (Various types, consolidated): Dodge to catch oneself on the edge of the pit, without falling all the way in
- Punji Sticks: Dodge to detect them at the last possible second and avoid impaling themselves. Can't be "triggered", so not really relevant to the first question
- Punji-Stick Drop-Fall Trap: Dodge to avoid being hit
- Swinging Log: Dodge to dive out of the way
- Barbed Wire Barrier: Dodge to avoid running into it
- Rock Slide/Log Fall: Dodge to find cover at -8 (already covered in the book)
- Crossbow Trap: Dodge per projectile
- Snare/net/bear traps: Dodge to avoid putting your foot in the trap
Additional traps not covered in the GMG
The following are some additional ideas for traps I've had, but am not sure how best to implement in-game, in terms of damage, escaping and avoiding them:
- "Shrinking room" trap - either the ceiling or the walls slowly begin to constrict, with or without razor sharp spikes for extra nastiness. The victim only has limited time to escape, either by finding a shut-off mechanism or some means of escaping, either left in there by the trap maker deliberately out of a sick sense of fun, or just available due to poor maintenance - a loose block for example
- Drowning trap - much like the previous, except the threat comes not from being crushed, but from being drowned in a fluid (usually sand or water) with which the chamber is suddenly inexorably filling
- Swinging/oscilating blades trap - anyone who's ever played Skyrim should know what I mean, not complex to defeat - just dodge between the blades - but nasty if you get it wrong. A variation on the Skyrim blades trap would be one where buzz-saw type blades repeatedly move back and forth at floor level.
- Poison dart trap - probably some variation on the crossbow trap? The hail of darts should not, to my mind, be terribly deadly in itself, but they're almost always tipped with nasty poisons
- flamethrower trap - again, like the ones in Skyrim
- magic rune trap - step on the magical symbol, get hit with some nasty magical effects (fire or lightning for example)
- Collapsing ceiling trap - once triggered, the entire stone or wood ceiling of the room collapses on the intruder. Probably a variation on the Punji deadfall trap? Except rather than a single object you might dodge, it's the entire ceiling of the room you're in. Conceivably if it began to fall from one end, the character could flee to the far end of the room and open a door, though one might think that the designer wouldn't incorporate an easily-unlocked door, if he wanted the trap to reliably harm those caught in it.
- Rolling boulder trap - Indiana Jones-style trap, where a massive ball of rock rolls to crush the intruder. Only way to avoid it would be to flee the boulder until the tunnel narrows or turns too much for it to keep rolling (which in IJ, it does for narrative convenience), or to find a gap in the tunnel that you can retreat into while the boulder rolls past you
Any other trap concepts I haven't thought up yet would be greatly appreciated.