Strike plate reinforcement can involve reinforcing the
strike plate and/or the door frame, to prevent the strike plate from being
rammed out of the frame.

Door reinforcements

various products are made to prevent delamination and or
splitting of the door. A sheet steel plate can be placed behind or under the
deadbolt and wrap the door edge to prevent breaking the door around the
deadbolt. Heavy-duty products that place plates on either side of the door tied
together with screws or bolts can be used to prevent delamination.

Door chains

allow the doors to be opened slightly to view outside
while still remaining locked.

Secondary internal locks

sliding bolts, hooks, specialty latches, metal blocks, or
bars mounted internally.

Hinge screws

longer or specialized screws that prevent the door from
being simply pulled out after removing the hinge pins. Often the hinge pin
itself is screwed, from the inside while the door is open, into the hinge to
prevent removal of the hinge pin without first opening the door.