Deputy Steel is owned by Megaton as a whole but entrusted to Lucas Simms and apparently maintained by both Lucas and Harden Simms.
Interactions with the player character
This character has no special interactions.
If the Lone Wanderer has a Science skill of 75 or more, they can deactivate both Deputy Steel and Deputy Weld using the computer terminal in the armory to avoid wasting ammunition or getting hurt. If a Stealth Boy is used before entering, the Lone Wanderer might sneak over to the terminal undetected to deactivate Deputy Steel then loot the place without any conflict.
Effects of player's actions
If Deputy Weld, Megaton's Protectron guard, is destroyed after Broken Steel is installed, Deputy Steel will assume Deputy Weld's post. In the Game of the Year edition this is not the case: if Deputy Weld is destroyed, Deputy Steel will remain in the armory. However, Deputy Steel will still show up if the Lone Wanderer attacks Deputy Weld, as will Lucas Simms.
If the Lone Wanderer enters the armory in Megaton, Deputy Steel will become hostile.
Lucas Simms mentions Deputy Steel to Harden Simms (his son), saying, "So, ummm... I noticed Deputy Steel looking a bit shinier than usual. You polished him up, didn't you boy? He he he. Good work, son. Good work."
If one enters then exits the armory, he will follow them outside, thus causing the town to turn hostile towards the player character.
Simms is a fan of the Wild West (his dad used to read him stories when he was a kid). He took on the title of sheriff and named the robot his deputy mostly to live out his childhood fantasies.
Sometimes, when one attacks him he says "What is your major malfunction, maggot?", which is a reference to the 1987 movie Full Metal Jacket. Gunnery Sergeant Hartman says this right before he is shot by Pvt. Lawrence ("Pyle").
Sometimes, upon fast traveling to Megaton, he will spawn right in front of the player character instead of inside the armory.[verified]