In response, I too carry 550 line or thicker Kevlar cord, as well as duct tape, but as Chaos noted, speed is of the essence in the type of situation in which they may be employed. And as UTA correctly observes, the card trick doesn’t always work and if it fails, you can be stuck in the stairwell.

Related Observation: I’m sure most of our colleagues on this forum, take note of the location of emergency exits when they enter a new theatre, restaurant, entertainment venue, etc. . Until my recent retirement, my work often took me to other offices in larger office buildings. If I was unfamiliar with the building , I took the advice I had previously read on an Internet forum ( which one ,I don’t remember), to take a photo with my cell phone, of the escape map ,wall posted by exits and elevators.