Warmonger

 is a perk added to Fallout 3 with the Broken Steel DLC.

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. This perk can either be extremely useful or a complete waste: it is useful, for example, if you have missed your chance to get some of schematics (Herbert Dashwood killed, Doc Hoff killed, etc) and can also save you the 30 Nuka Cola Quantums required for Sierra Petrovita's schematic (unless you want to complete the related quest). But, since the full benefit of this perk can be acquired simply through exploration and trade (especially by the time you get to the required level), it's merely a convenience unless you want to create a truly absurd stockpile of Nuka Grenades. The quantum chemist perk can also allow you to create Nuka Grenades. It should also be noted that taking this perk will return all previous weapon schematics to the 'misc' section of the player's inventory, which can then be traded for a decent amount of caps.

Bugs

 * (Needs confirmation) 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 Shishkebobs 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.