system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Trek] How can a holographic bullet kill somebody on the holodeck? How can a holodeck misfuction so much that it creates a being that can then leave the facility ala Prof Moriarty?
gpt
The Holodeck creates "hard light". If you can use the Holodeck to create a chair that you can sit on, then you can create a bat to hit someone upside the head. Or a bullet.

Further, spoiler here, but Moriarty never left the Holosuite program. He left a simulation of it, and walked onto a simulation of the Enterprise outside the Holodeck.