Samuel Hayden

Dr. Samuel Hayden is a character in the Doom, a high-ranking UAC official who formerly oversaw the Argent energy research projects at the Argent facility on Mars. After an unknown incident during construction of the facility's Argent Tower which caused him to develop cancer, he was forced to replace almost the entirety of his body with cybernetics. He was first officially shown by id Software in the game's official launch trailer greeting the Doom marine after he awakens from an apparent slumber. In exclusive footage released by video card manufacturer to demonstrate the performance potentials of the then-new  graphics API in id Tech 6, he can be heard acting as an advisor to the marine, speaking about Olivia Pierce, to whom he is now an enemy. He states that he had hoped she would "rise above their influence," referring to the demons from Hell which she instead unleashed.

Hayden is adamant in defending his original research projects into Hell and its Argent energy reserves, stating that it was all in mankind's best interest, and that the sacrifices made would have been worth the cost, if his other staff had been able to resist the corrupting influences of the demonic dimension. While he seems friendly, whether or not he can be trusted must be regarded as a question.

Samuel Hayden's voice acting is performed by Darin De Paul.

Recruitment of the protagonist
Hayden meets initial resistance from the Doom marine when trying to recruit him to fight against Olivia and stop her planned opening of the portal to Hell in his preferred manner, with the soldier violently destroying every device he tries to use for communication. Dr. Hayden ends up forcing the marine's hand by cutting off his access to the satellite communications array and offering him the information he seeks in exchange for his cooperation. Once actively allied, Hayden has VEGA give the marine access to all of the facility's Argent energy capsules.

Character origins
The original plans for Doom 3 called for a character named General Hayden to function as a secondary villain, initially appearing to be the cause of the invasion and taking the place of Dr. Malcolm Betruger in several of the game's scenes, only for Betruger to be later revealed as the true mastermind. While dropped from the game, with his roles dispersed between those of Betruger and Sergeant Kelly, he was retained and revived in the Doom 3 novels.