Monster: Wood Crabs

[Mr Dalton]

Originally Posted by johndallman

Answering that needs more information:

• What's the campaign style? Clearly fantasy of some kind, but do you have a more specific description?
• What magic system(s) are you using?
• What was their starting point level?
• How many points have they gained?

I started with 200 point builds, but the campaign has been going for a long time now, so I'm not sure how many points they've built up overall.
The campaigns style has that generic fantasy base, but with a kind of body-horror tone. The idea was supposed to be that the world is deadly and dangerous, which is why I shifted it from Pathfinder to GURPS after the first session. It's hard to make characters scared when you're built to be top-tier heroes.
Up to now, I've focused more on the psychological horror of it, because the setting in the world has a corruption element, where when you do something evil - regardless of motivation - you build up corruption and if it gets to high, you mutate into some kind of horrific monster (a la John Carpenter's The Thing). So, the real threats have been the risks of losing yourself, more than the risks of the monsters. After all, there's no evil in killing a mindless monster that only hurts others around it, so they were really just more of a world detail early on - a constant reminder of what you could become if you were careless with your actions. But the things they're running into now are more meant to be actual guardians of the world's dark secrets, so they manifest as physical threats now as well.

I suppose, with that in mind, the idea should really be about avoiding engagement unless you can manipulate the situation to your advantage, rather than taking things head-on, so the actual power level of the monsters doesn't matter so much as encouraging the players to approach the situation correctly. Which they've been doing all along. Even among the weaker monsters, they try to avoid melee for as long as reasonably possible.
And they've heard of the wood crabs before. They ran into some lumberjacks who talked about them, so they aren't flying completely blind. They know at least that they're ambushers that are really good at blending in with the forest.

As for magic, the caster in the group is a witch, which is using a custom system of mine that trades on superstition for power. Her magic is more about what she can convince others she's capable of, with some additional limitations to balance out the potential for abuse. Essentially, she's a slow spontaneous caster who can craft any spell she wants on the fly - provided she has the time for it - but I've modified casting times to favor buffs and debuffs to fit the witch vibe. She's the ultimate support caster, capable of solving a lot of non-combat situation if they're willing to wait for her to finish her spells, but in combat, has to fall back on potions, or relying on buffs and debuffs, with only a few modular spell slots (3 in her case) to put some bigger spells in case she needs to cast something big quickly. Big, damaging attack spells are usually out of the question, since that's not the superstitions people associate with witches.

I suppose if I make them impossible to spot while standing still, but leave clues for them to notice something dangerous is nearby - like corpses of other adventurers - they could come up with a clever plan to expose it, like maybe throwing something into the area to trick it into attacking, since it only has vibration sense and just attacks anything that enters the area that's large enough to notice.