I have been trying to think about what trap's could be used to capture a player and a few come to mind, the first would be really interesting to see but I am not sure if it could be done I can't recall if I have seen it in a game similar to STN.
Twitch Up Snare: These Snare's are typically used to pull up a animal that has been caught in a snare out of the reach of most scavengers and predators. They are used with varying sized branchs depending on the intended prey and held down with rope or cord. A wooden peg attached to the rope connects with a peg in the gound, the rest of the rope or cord is tied in a noose snare so that when it is disturbed and the peg is released the noose tightens around a neck or foot and yanks the prey into the air with the pent up energy in the branch. You see these a lot in movies when they are used to trap one of the charecters, if you have ever seen The Rundown the two main char's Beck and Travis are caught in two of the trap's.
If you can't use a large tree branch attached to a tree you could screw a large piece of wood to a tree like in this pic.
Human sized twitch up trap's could only be used on large trees with fairly large branch's or piece's of wood.
Some other things you could do would be trap's including tranq dart's if they add them in.
I have a ballistic re-bar trap in my random trap thread and the rebar could probably be replaced with tranq dart's. There is also old arrow traps that could be modified to shoot tranq dart's. I can't remember if the first pic has been suggested before I recall seeing it.
These types of traps could have modified arrow's with tranq dart head's, the arrows could also be fired like regular ammo. Another smaller trap could be made from a wood board, some strap's and a crossbow pistol activated by a tripwire.