Bypass Methods
Sometimes you defeat the latch or the mechanism instead of picking the pins. Quality deadbolts, security pins, sidebars, and anti-bump / anti-shim designs defeat most of these — but on cheap or misinstalled hardware, bypass often beats picking on speed.
Latch slipping (loiding, carding)
On a spring latch with no deadbolt and an exposed angled latch, a shim / shove knife / stiff card slides between frame and door and presses the latch back against its spring — the door opens.
Doesn't work on deadbolts, or on latches with a deadlatch plunger — the small secondary bolt beside the main latch that locks the latch in place when the door is closed.
Latch resting
A spring latch with an exposed, angled (bevelled) face. The small deadlatch plunger beside it is NOT depressed here — meaning there is a gap, and carding can work.
Shackle shimming (padlocks)
A thin waved metal shim slides down between the shackle and the padlock body to release the locking pawl. Double-locked padlocks — where both sides of the shackle lock down — need one shim per side.
Modern padlocks defeat shimming mainly with ball-bearing locking in place of the swinging pawl, plus shrouded bodies and tight tolerances that deny the shim a path to the latch. (Hardened steel resists cutting and prying — it does nothing against a shim.)
Pawl locked
Inside the body, a spring-loaded pawl sits in a notch cut into the shackle leg, holding the shackle down and locked.
Comb picks
On cheap locks, a comb pick pushes every pin stack up above the shear line at once — both drivers and key pins end up trapped in the housing and the plug turns freely.
Any lock with correctly-sized pin chambers (i.e. most modern locks) defeats this — there is not enough room in the housing for both pins.
Pins at rest
A standard pin-tumbler: driver pins cross the shear line into the plug, so it is locked.
Bump keys
A specially cut "999" key — every cut at maximum depth — is inserted, then pulled back one pin position (or held just short of fully seated). With light turning tension held, the key is tapped sharply so its ramped peaks strike the key pins; the energy passes to the driver pins, which momentarily bounce above the shear line while the key pins (with nothing above them but air) stay in place. In that instant the plug turns.
Anti-bump pins, sidebars, and high-security keyways defeat bumping. A good deadbolt is not bumpable.
Bump key inserted
A "999" key — every cut at maximum depth — sits under the pins with light turning pressure held on it.