Crysis is based in a fictional future, where an alien race has invaded Earth. The single player campaign has the player assume the role of Jake Dunn. Dunn is a United States Delta Force operative, who is armed with various futuristic weapons and equipment, most notably a "Nano Muscle Suit", which is an artificial and technologically advanced exoskeleton, inspired by the United States' Future Warrior 2020 program, according to Bernd Diemer, one of Crytek's senior game designers.