I would like to add a new perspective to □ Tripwire. Players might think of a time bomb trip wire with 1 count by combining with □ Improved Timer and □□□□ Explosive Device (additional 5 XP investment). But you can stop at just □ Tripwire. By eliminating any enemy appearing in the same turn they appear utilizing -1 Fight, -1 Evade, the trap lasts indefinitely! If you want to put minimal XP in the trap this is a strong 1 XP wonder.
My friend was attempting to left □□□□ Explosive Device around with some timer and Resign, leaving the rest of the team to lure enemies to the bomb and fight using the reduced fight and evade. It was a cool but unfortunately the rule says the trap must be removed following that player's elimination (resign). (Same for attached Map the Area, Breach the Door, etc.)
Control of Attachments : Player retain control of the card attached to location (which is a scenario/encounter card).
Elimination : The cards he or she controls in play and all of the cards in his or her out-of-play areas (such as hand, deck, discard pile) are removed from the game. Any card that player owns but does not control that is in play remains in play, but if that card leaves play it is removed from the game. (The trap is both owned and in control, so it will not get remain in play.)