I had a dream someone broke into my grandma's house but we ended up defending ourselves and killing him by denting his skull with a small, round, blunt object.
Dreams about intruders or burglars usually symbolize some sort of intrusion or invasion into a person's personal/private life or boundaries. The fact that you defended yourself and took action against the intruder in the dream shows a desire to protect yourself and what you hold dear.
Killing someone in a dream can sometimes symbolize the need to eliminate a negative aspect of oneself or one's life. In this dream, the intruder may represent a part of yourself or an external situation that you need to confront and eliminate.
The use of a small, blunt object to kill the intruder may suggest the need for a small but effective means to deal with a problem or conflict in your life. It could also symbolize a need for precision and careful planning in dealing with a situation.
Overall, this dream may indicate a need to safeguard your personal space and boundaries, and to take assertive action in eliminating negative aspects of yourself or situations in your life.