Legendary Modification

At any weapon workbench, select the weapon, then choose the 'Legendary Mods' category (it appears as a new tab). You'll see a list of effects like 'Furious' (increases damage per hit). Each effect requires a 'Legendary Module' (crafted at a chemistry station using 1 Nuclear Material, 1 Circuitry, and 1 Gold). You can also scrap legendary weapons to recover modules—just dismantle any legendary weapon you find to get 1-3 modules back.

If you have a legendary weapon with an effect you like, use the 'Legendary Modification' console command to extract it: open console, click the weapon, type 'amod <effectID>'. To apply it to another weapon, click the target weapon and type 'amod <effectID>'. For example, to get 'Two Shot' (ID: 001CC2A5), type 'amod 001CC2A5' on the new weapon. This is faster than crafting if you have the base effect already.

In survival mode, legendary effects like 'Rad Powered' (increase damage with higher radiation) can be overpowered. Use the mod's config file (found at 'Data\LegendaryModification.ini') to adjust the 'ModuleCostMultiplier' setting. Set it to 2.0 to double the component cost, making legendary crafting more expensive and preserving game balance. Edit the file with Notepad and save before launching the game.