Most people attack things out of ignorance.
I was in high school in the early 80's, and D&D was somewhat in it's hey-day (or something like that), it also was a time where, since it was very popular (like pokemon and harry potter have gone through), it's been attacked by many Christian and so-called Christian groups.
Much of the information that was spewed forth at the time (and in print) was either wrong or only half-true. Many times they'd say something was in the game, and I knew it wasn't. Many of the arguements where rather poor, relating mostly to a "guilty by association" type of tactic.
I think that a couple of things govern the acceptabilty of D&D as played by Christians:
1) Who's the crowd you play with? For me this was the main reason I haven't played it since a few years after I moved down here. The only people I knew who played, well.... turned out years later the guy is a satanist! Needless to say, since I wasn't a... 'cuze my language... bad***, well... I took some riticule.
2) Your personal view/attitude/acceptability of the whole "magic" thing... D&D is based in a fictional world, and I've yet to see hard proof that the magic system is based off of this worlds magik, however I haven't been looking either.
3) Your play style. I've usually taken the approach of playing somewhat how I would play if I was there, however I've been know to do things in games like Icewind Dale that I wouldn't do in real life... it is only a game after all
I personally don't recommend playing characters outside of how we should normally live our lives. But you'll have to feel that one out on your own.
4) Most importantly, what is God telling you? Most of us know what is wrong, we're real good at pushing that aside when it's something we want to. Part of what we need to do as Christians is learn to listen to God in all things (Lord knows I'm not perfect on this).
One last thing, have you ever heard of "DragonRaid
?" It's a Roleplaying game for Christians... sadly I've not had the opportunity to play it (or even own it yet, though I might order it soon).
My biggest problem is finding people to play with... sadly while I might be able to talk my way into a game of D&D with the guys at EB (those who play), I'd have to think/pray about even considering it since I don't belive any of them are believers (though it might make a good witness)... in most Christian circles (i'm an "older" fella) it doesn't seem that people in my "age group" do much in the way of playing this sort of thing (yet there are plenty of people my age in the "secular" world who do, go figure). This was my problem with the Redemption card game.
Oh well... Hope my rambling was good for something