The game features the standard gamut of first-person shooter weapons such as assault rifles, along with sci-fi additions such as the Gauss rifle, or Alien weapons, such as the Alien Molecular Accelerator. As mentioned earlier, all weapons can be modified with attachments; these attachments may be given to the player by default, acquired from picked-up weapons, or purchased in multiplayer. Once acquired, they can only be removed through death or scripted loss of inventory if in story mode, e.g. If during normal play, a player attaches a flashlight to a rifle which is later discarded, it is not considered gone and will still be available in the future.
Attachment options are given a fair amount of leeway even if the end result may seem strange. For instance, a 4x/10x sniper scope can be attached to the buckshot-firing shotgun. Additionally, most weapons can adjust their firing modes. Crysis also incorporates some features that have appeared in other recent shooters, such as being able to lob hand grenades without needing to formally equip them first, or accounting for already-chambered rounds when a reload occurs.