I played ME2 without having played ME1. I still haven't played it. I can't comment on the gameplay differences, but ME2 is easy enough to understand what's going on without playing ME1.

@jetmet: I'm a huge ME1 apologist. It's a fun game. If the combat turns you off, just jack the difficulty all the way down and push through it. I've probably played ME1 over 6 times. While it's not needed to understand ME2, it's story and characters are worth it on their own. Plus, you won't really appreciate how much the franchise changed without starting at the beginning. It's not like the series was an unknown, niche thing before ME2 came out.

If you do try it out and get stuck, I can offer some gameplay and character build advice.

I never played Mass Effect 1, but some might say Mass Effect 2 is one of the greatest games ever made.

Mass Effect was created specifically as a trilogy. It is meant to be experienced as a trilogy, starting at the beginning. Save transfers are one of the defining elements of the series, along with the story. ME1 may be slightly less casual friendly than ME2, but let's be honest here, it's still not exactly a super deep RPG.

Anyone new to Mass Effect should always start with the first game. Yes, it's a little clunkier, the combat isn't as good, and the character development isn't as in depth as the later games, but it's the beginning of the story for a series all about story.

I would offer my road to the series:

start on 2 and don't worry about completing everything.

as I liked the game a lot and wanted to see more, I went back to 1 on a different class.

then I transfer that save to 2 and replay everything again (different class, different romance options, lots of different choices, and seeing the save transferred differences)

2 being more polished probably will be an easier hook. But 1 has the best writing of the series.

Mass Effect 1.

Mass Effect 2 may be the best playing game in the series, but Mass Effect 1 is the best Mass Effect.

I don't exactly know what "a casual" means in this respect, but you can tweak Mass Effect 1's difficulty to be fairly easy if that's the sole barrier for entry.

Personally, I think playing through this series cold without experiencing the original sounds absurd.

I don't think ME1 is a particularly good game anymore but like.. don't start a trilogy in the middle.

Your link does not go to the place you want it to. Also, it took me a minute to figure out what you meant by a casual.

As for the question, I would say you can start your dad on Mass Effect 1 as long as you give him plenty of warning. If you are in a position to play through the game with your dad, I would recommend it fully.