This post is pretty self explanatory! Growing up, my cousin, J, was SO creative. Every time we spent a weekend with his family he would build his own board game.
At my ripe age of 6, the games were fairly simple. But by the time J was 10 or 12, his games were amazing! They would often be three dimensional, with trap doors, actual booby traps... it was way more fun to play his games than "real" board games that had become ... well... boring!
For Halloween, we found a printable game that you can color and create a "Spooktacular" Halloween board game, and this has inspired many of our own home-made board games since.
Since we don't have chutes and ladders, we made our own version last week.
You could make it way more complicated for older kids to introduce ANY concepts you are learning about. If you are learning about a certain theme, it could have trivia questions, printed pictures glued on, etc. Great math concepts are introduced through games also!
You could have flap doors (you take a piece of cardboard, fold a small rectangle of one of the sides and glue that folded piece onto the game board with a hot glue gun....) and use real people or cars or animals as the pieces.
I love fun ways of learning where kids don't even know they are learning!!