Tonight the group chanced upon a trap. To avoid overtly spoiling the encounter, I won't give too many details here, but may give out more information in comments so be advised of the possibility of spoilers!
The trap could only affect nearby PC's but dominated them, so it was kinda nasty.
The warden was able to get himself free and retreated. From a safe distance he formed a rope into a lasso and proceeded to try and free his companions by lassoing them and pulling them free.
I didn't believe there was any formal guidance in the rules for such an action, but I was able to ad-lib something fairly reasonable. My fear is that what I came up with was potentially too strong. I don't want to incent the PC's to go around lassoing every monster after all :)
Are there any rules about lassos in D&D4?
Has anyone else come upon this situation? If so, how did you resolve it, and was it satisfactory?