Trapped: Giant Spiderweb
If you’re going to fill a cave, dungeon, or forest with Giant Spiders, there has to be a way for them to catch their prey, doesn’t there. To go along with my custom 2nd level arachnid I created a Giant Spiderweb trap designed to snag unsuspecting adventurers. Because it does no damage and is essentially one-shot (I reasoned that anyone escaping essentially destroys the web in the process), I decided it was a Minion trap and worth 25XP.
Level 1 Minion
Trap: A giant spiderweb.Perception✦ DC 15: The character notices the spiderweb.Nature✦ DC 10: The character identifies the web as the creation of a giant spider, and recalls its properties.TriggerThe trap attacks the creature when it enters its square.AttackImmediate Reaction MeleeTarget: The triggering creatureEffect: The target is restrained (cannot move, grants combat advantage, -2 to attacks).Countermeasures✦ Acrobatics DC 10 or Athletics DC 10: A character restrained by a web can make a successful check as a standard action to free themselves from the web. The web is completely destroyed in the process.
✦ A character can attack the web (AC 4, REF 4, FORT 12; hp 15; vulnerable 5 fire, 5 acid; immune poison, psychic, necrotic, and attacks against will).
In play, the trap works well stretched across entryways or narrow spaces. And of course, in the process of trapping the adventurer, the trap is also likely to inform its creator (the aforementioned Giant Spider) that dinner has arrived.
Update: The Monster Manual 3 describes a terrain called web sheets (MM3 p.183) which is very similar to my Giant Spiderweb Trap design. It makes an attack versus reflex (which the Giant Spiderweb Trap should probably do to be consistent with trap design) but only immobilizes victims (can’t move). I think restrained (can’t move, -2 to attacks, grants combat advantage) is more consistent with how a giant web would work (and be more useful to the spider spinning it) but to each their own.