Four progressively aggressive methods to extract a screw when the head is too damaged for a normal driver.
Switch to a driver that fits snugly — a stripped screw often just needs more downward pressure and a fresh bit. A manual screwdriver gives you better feel than a drill.
The rubber fills the gaps in the damaged head and adds grip. A piece of steel wool works as a backup.
You only need a slot deep enough for the flat-head to catch — about 1mm. Go slow to avoid cutting into the surrounding material.
If enough of the head is above the surface, clamp locking pliers tightly onto it and turn counterclockwise. For flush screws, use a screw extractor bit.