The ESP file extension is used by the Fallout 3 and Fallout: New Vegas computer games.
They are first-person role playing games. Both are these games are set in a post-apocalyptic version of Vegas that is inhabitant by mutants, bandits and other unsavory characters.
.esp File Extension
Developer:
Bethesda Softworks
File category:
What are esp files & how to open them - Fallout 3 Plugin File
File category:
Developer:
Bethesda Softworks