With the framerate of my old laptop (10-20 fps), I am able to run through closed doors, fences and even some walls, when I am running (2x"W") against them.

Not rarely, this results in unexpected deaths because I glitch through a wall while in some upper floors.

A detection and "roll back system", if this is "physically possible", depending on the position before and after the lag and the objects (e.g. wall) inbetween might help, if it's not to CPU intensive.