It would be great to discuss all of this by referring to the scriptures.
I'd like to say there is a happy balance.
1. It is not our place as "Christians" to judge the world but rather to exhort each other (believers) to live a life glorifying to the Lord we claim to serve. It is written that we should strive (I doubt any of us have reached this yet) to do all things to the glory of God.
2. Involvment in fantasy fiction, such as Lord of the Rings or Harry Potter cannot be directly linked with witchcraft, which is real and people still practice it.
3. Personal choices of involvment, whether music, games, etc., are open to various opinions and should not be strictly judged by other men.
4. It is written that we are called out of the world and are no longer to be like the world. "Christians" would do well to to be more consecrated unto their Lord, instead of making excuses as to why it is okay to be like those who do not serve that Lord.
5. If we are seeking God with all of our heart, mind, soul, and strength, then will we keep stuff in our life, whether sin or not, that will hinder us in that persuit?
6. So, it is not a matter of "legalism" but of fruit. Jesus said, "If you love me, obey my commandments." We would do well to focus in on the obvious commandments, the basics. Once we have the basics down, we should continue growing by going deeper. The "legalism" message above should be balanced out as "grace" is not a license to disobey. Jesus said there will come day when we will all be judged before him and to MANY who say, "Lord, Lord"- meaning they believed in him as Lord - but he will respond, "Depart from me you WORKERS OF INIQUITY, I never knew you."
7. The best way for us to admonish others to holiness, once we allow the GRACE of God through Jesus to give us power to live holy lives, is to live the example. If we are living the example, taking the log out of our own eye, then maybe we can point out the speck in another's eye.
In closing, if you are absolutely sure that you are not hindered in loving Jesus (remember that takes obedience to commands), than continue to play your games. A few years ago, I still played some computer games that had sorcery and magic in them. I was serving God at that time and was quite successful at the level I was at in ministering to young people. However, as I grew spiritually, I threw off such weights that hindered my progress and no longer play such games - not because of legalistic observance of commandments, but because of my love for Jesus, which overrules all others.
So, the best thing for us all is to love God and love each other, yes that takes obeying HIS COMMANDS. However, we should be quick to encourage others to follow Jesus truly while being slow to condemn and criticize what we perceive as weaknesses.
I hope you understand I am not putting any down or taking sides, but rather trying to speak balance into this discussion so we may be in unity and love.
Have a great day!