Warmonger

 is a perk added to Fallout 3 with the Broken Steel add-on.

With this perk, all custom weapon types become available to you without the schematics. Taking this perk immediately gives you the level 3 schematics for all weapon types you did not already have.

The usefulness of this perk is debatable. One one hand, it will allow you to collect schematics you have otherwise permanently missed the chance to get, in particular the Bottlecap Mine schematics kept in Herbert Dashwood's key-locked safe and the Nuka Grenade schematics sold by Doc Hoff. It also allows you to save the 30 Nuka Cola Quantums required to get Sierra Petrovita schematic (assuming you have no desire to complete the related quest), meaning a total of 90 more Nuka Grenades you would have otherwise lost. It should also be noted that taking this perk will return all previous weapon schematics to the Misc section of the player's inventory, as well as make additional ones unnecessary, which can then be traded for a decent amount of caps.

On the other hand, most of the schematics can be acquired simply through exploration and trade (especially by the time you get to the required level), and only in the case of the above two schematics have any substantial effect on your ability to craft items. The Quantum Chemist perk will also allow you to create Nuka Cola Quantum from regular Nuka Cola, creating an unlimited supply since the drink is sold and restocked by certain shopkeepers.

Bugs

 * This perk works perfectly for the Nuka Grenade and Bottlecap Mine. However, for all other schematics, you must have at least one schematic for the weapon before taking this perk or it will not work correctly and will produce the weapon as if you had only the level one schematic. For example, if you had a Railway Rifle schematic prior to taking this perk, but you did not have any Shishkebab schematics, then taking this perk will cause you to make Railway Rifles as if you had the level 3 schematic, but Shishkebabs as if you only had the level 1 schematic. It is thus advisable to still acquire at least one schematic for all weapons other than the Nuka Grenade and Bottlecap Mine prior to taking this perk. (Unconfirmed) In the XBox 360 version, it functions as intended.