Isaac Briggs is a Field Operator of Fourth Echelon. He is a former CIA officer and an expert of tradecraft, advanced weaponry, stealth, sniping, armed and unarmed combat tactics. Briggs shows exceptional skills in covert tactics and espionage, being very skilled in all types of firearms as well as showing stealth skills similar to Sam Fisher. He is able to climb ledges and is adept at mountain climbing, despite only training indoors prior to his first mission working together with Sam Fisher in a cooperative mission. It is shown that Briggs possesses very skilled marksmanship abilities, as he was able to take out multiple foes during his recovery of Fisher from Majid Sadiq.