Or are you just trying to due to the game's large update sizes? RaGEZONE - MMO Development Forums
These files usually contain "Quality of Life" improvements like faster movement, increased carrying capacity, and "no weather" patches.
Because Icarus uses the Unreal Engine, small patches can sometimes trigger massive 50GB+ file re-verifications. Community members often discuss manually "rar-ing" or compressing their game files to save space or share patched files with friends who have slow internet.
You typically extract the contents into a custom \mods folder within the game's local directory. 2. Private Server Files (Riders of Icarus)
Most reputable modders host these on GitHub or the Icarus Discord .
Are you trying to for the survival game?
This is the most common use. Players of the survival game Icarus often share as .rar or .zip files.