This past Friday my youngest and I engaged in a fierce and brutal conflict on the hard wooden floor with the classic game Battle Masters. It was his first time playing the game and likely not to be the last.
Picked up Battle Masters about 24 years ago... that's 3 years before my first son came into the world.
We played with a bit of house rules to keep my son from getting lost in details and having to deal with me using more than luck. The only terrain we paid attention to was the river and it's fords along with the castle. We kept the ogre simpler than it is even in the rulebook, but the big fella didn't get much use. We also split the main deck into halves one for the empire and one for chaos and we alternated turns as I've learned years ago it can be both frustrating and boring waiting to take a maneuver your forces under the regular rules, I like the card based move this unit now but it works better alternating card draw of a deck for each army.
My son was impressed by how much stuff there is in the game, wait till he gets a chance to use all the rules and maybe even "campaign" play.