Gallows Humor

Find out Knight Captain Gallows' real name is a minor quest in Fallout 3.

The Betting Pool
Talk to some of the members of the Brotherhood of Steel in the Great Hall after gaining entry to the Citadel. They will tell you about a betting pool to try and guess Gallows's real name. You can ask Knight Captain Gallows about it after hearing about the bet. If your speech skill is high enough you can convince Gallows to tell you his real name. After you find out his name you should speak to Paladin Glade, who is running the betting pool. Glade can be found near Gallows in the Great Hall in the A Ring area.

Reward
The reward is the current betting pool, which has risen to 1000 Caps.

Note: This mini-quest can be done up until the march of the robot to the purifier during the main story line.