The license "Star Fleet Battles" operates under does not allow for direct reference to the characters and detailed events of the "Original Series". As such, official material does not include references to Kirk, Spock or use the USS "Enterprise" directly, though the latter is included in ship listings. This has not prevented oblique references, such as a comment about the first Gorn-Federation meeting as involving “two young captains who fired first, and faced embarrassing questions later.” Other references are monster scenarios loosely based on the planet killer from "" and the space amoeba from "The Immunity Syndrome".