My Spanish book is saying that the phrase "to play checkers" is "jugar a las damas." Similarly, "to play chess" they're saying is "jugar al ajedrez." Why do we have to have "a" in there? I thought "a" was only supposed to be used before people. Is it possible to just say "jugar las damas" or "jugar el ajedrez" instead?
Also, is it possible to drop the definite articles in these phrases? Could you just say "jugar damas" or "jugar ajedrez?" I'm not really sure when to use the definite articles and when not to use them!