Sam isnt a playable character though. You do a joint OP with him but he's not playable. And you cant get his gear without buying it. Pass.
In Wildlands this is true same for the Siege and the Future Soldier additions to it.
In Siege if you pay for him through season pass or in game you play as Sam Fisher.
Sam Fisher is in seige now? How? He's like 60 years old at this point. What's his offensive ability supposed to be, forcing the enemy team not to melee him because they don't feel comfortable punching out this old man?
So he is a Attacker, and his gadget is a camera that can attach to any type of wall unless electrified, and can see on either side of it. He also has his signature SC3000k rifle, and a silenced 5.7
Also, he is 63 years old as of Siege.
Sam Fisher is timeless. He only gets grizzled forty something old. He doesn't actually become a geezer like that groin grabbingTryHarder Viagra Snake.
In the lore he was singlehandedly taking out entire teams of Operators during the massive training session that had in the stadium. He is also held in high esteem by the Six team, and has had Finkas nanites put into him to counter his Athritis.
Finka who knows him because he worked with her father, even says that is Sam is there, he is there for a reason and only he knows why. he is also high up in the rainbow team, and is a member of their operational staff.
Bascially he is the most bad ass of badasses on the team. And is the oldest and still kicks everyone's ass.