My dad wants a game like Skyrim, any suggestions?
He has Skyrim, he told me to get him a game like it
tell him to do it his own damn self, he’s an adult
two worlds (not two worlds two)
Its for Christmas, no need to be rude
Fallout: New Vegas?
Got it already 
What’s his favorite aspect from Skyrim? The open world exploration? The rpg mechanics? The talking to different characters and having to make decisions?
The only games that play like Skyrim are Skyrim and the two 3D Fallout games. I’d go with what Maxey is suggesting.
There’s also Morrowind and Oblivion, but it’s generally frustrating to go back to an earlier game with less refined mechanics, so I wouldn’t recommend it.
The open-world aspect and the storyline starting right away.
Mass Effect series perhaps?
STALKER?
These aren’t really my kinds of games, but what about The Gothic series? Or Divinity 2?
Far Cry 3? Read Dead? Stalker Series? GTA? Arkham City? The Witcher Series? Fable? Mount and Blade is stretching it.
Are there clean language patches for those? My mom won’t tolerate any games with high levels of foul language
It has some instances of heavy swearing but they’re not very common. ME1 has none at all afaik. I think it’s fairly safe to play for the most part.
Honestly tell your mom to man the fuck up and deal with it.
What about the “partial nudity”?
Can’t handle a little sideboob with no nips? I mean, if that’s a problem, just avoid romances.