 A wide variety of both official and fan @-@ created modifications are available for Skyrim , generally made using the packaged Creation Kit . These mods might be distributed freely on file sharing sites like the Skyrim Nexus , or officially aggregated via the Steam Workshop 's controlled content distribution mechanism . The mods include features such as more vibrant night sky , new lighting systems , new characters and locations , user interface updates , and more . The first official Skyrim modification was The Fall of the Space Core , Vol . 1 , created by Bethesda in collaboration with Valve Corporation . It causes the Space Core – a fictional device from Valve 's video game Portal 2 – to fall from the sky and land in a burnt @-@ out house near Whiterun . The Space Core ( voiced by Nolan North ) acts as a non @-@ player character , following the player around the world of Skyrim and dispensing space @-@ related comments . 
