Light Step/Fallout 3

Light Step is a perk in Fallout 2, Fallout Tactics, Fallout 3, Fallout: New Vegas and J.E. Sawyer's Fallout Role-Playing Game.

Fallout 2 and Fallout Tactics
This perk is broken in Fallout 2. The 50% reduction doesn't affect every mine in the game, just the ones at Sierra Army Depot. It's slightly more useful in Tactics, assuming the player doesn't just disarm the minefield with a few shotgun rounds.

Fallout 3 and Fallout: New Vegas
The player's character never sets off mines or other floor traps with this perk. This does not affect any companions, including RL-3 and ED-E.

Traps affected include mines, tripwires, pressure plates and bear traps. Traps such as explosive baby carriages still go off, as do grenade bouquets if the player makes contact with the grenades, or shoots them.

J.E. Sawyer's Fallout Role-Playing Game
"Maybe it was the landmine that almost blew your leg off, or maybe it was the sight of your buddy in pieces next to you. Whatever the cause, when you meet the triggering criteria for a landmine, door bomb, or steel trap, there is a 4 in 20 chance per rank that it fails to go off anyway."

Each rank reduces the chance for a proximity-based trap to go off by 20% (60% total).