Opinions on using ideas from other stories and games

So me and my friend had a discussion recently about if its ok to use ideas based off of other peoples games, stories or shows.

His opinion is that if someone else came up with an idea, and it’s unique and original, that it is their right to use it and not someone else’s. Of course if its a generic idea thats been used many times before then their is no harm in using it.

My opinion is that if its a good idea and it’ll make your game better why not use it? That is assuming of force that it does nothing to damage or tarnish the original idea and that it doesn’t spoil the creators story by giving any thin away (spoilers suck). I also think that its important that you have some originality to the “stolen idea”, don’t just use something that we’ve all already heard of.
If you’re ripping off plot ideas my opinion is that you should only do it in very small parts or change it enough to make it your own (like in Choice of the Vampire).

Anyway I wanted to ask other people about the topic and get your opinions.

This sounds a lot like the discussion on the opinions on fanfiction thread. Maybe you could check out that one before making a whole new thread for what boils down to the same question.