Chess is pretty easy to learn, but extremely difficult to master. The hardest part of learning is figuring out how the knight moves. And arguing about whether en passant and castling is allowed.
HOLY NECROBUMP BATMAN
Well, I play Russian checkers online every day, it's a dynamic version of the game, and it is quite complicated against top players but much less complicated against lower-rated players compared to playing chess against lower-rated players. In Russian checkers, if certain squares are occupied, even early in the game, then a lower-rated player is bound to lose. But chess is always full of surprises even if you take control of the centre. Still, I've got a book of tactical solutions in Russian checkers and it contains ca. 380 pages. So nothing can be oversimplified. International draughts is a different story.
Chess may seem easy in that every move in itself may present a threat for the opponent's pieces or an attack on important squares, a sort of self-sufficiency of moves and pieces, but it's just an illusion which disappears quickly when you're facing a strong opponent.
Bridge (the card game) seems to be rather complex.