The witcher 3

Simple answer: Yes. The Witcher 3 is the sequel to The Witcher 2, and The Witcher 2 is the sequel to The Witcher. The whole Witcher universe is very complex and story rich, with many references, events and characters. So, if you really want to enjoy the full experience, then yes, you need to play the prequels.

You should get them anyway, they're excellent RPGs, if you like that genre.

You can play the game without playing 1 and 2, and you would enjoy it and would understand what is going on. You would enjoy it more if you play 1 and 2. And those 2 games are great and well worth playing. And both are cheap.

You want know the lore because half of witcher saga is about the lore, the other half is killing monster and get some girls cards... uh i mean relationship, witcher 1 and 2 worth a ton to play the 2nd game in special but i like the first a lot too.
About Bioshock i do think the first game works a lot better as horror than infinity, one of the rare games that make me jump the chair when you enter a room all the lights go off and dozen of creeps jump on you, very damm good way make someone jump.

Of course not neccesary, but I would certainly recommend playing 2 first (not 1, unless you mod combat).