I don't like the idea of mini games. I'm tired of having to play the same old games and puzzles in every little adventure game. I want something new and original, or at least old and neatly disguised. In Quest for Glory 1 they had the Mage's Maze game which was fun. It involved your character's skills in an original mini-game. The other problem with mini games is that they detract from role-playing. you have to be yourself to complete the mini-games. I suck at chess, yet why can't my mage with 112 Intelligence win at it? Similarly a charcter with high Agility should have a better chance at winning darts. But if the character plays them, they're not really mini games anymore, just challenges with prerequisits.
Idea:
The more intelligent you are, the easier the chess game is!
Or
You chose if you want to play the game yourself or let your PC do it (depends on Intelligence)
But like juggut said, you do not HAVE to play it, ok? What if you encounter a deamon K'hazpahrow who wants to play chess with you? You can always refuse if you suck at them.