As accounting goes, it is simplistic, but it establishes some of the basic concepts. The Gathering , the card game that has taken the world by storm, has an important lesson in income management hidden in it's play. The player must carefully judge which cards to bring into play, based on their cost in mana, how useful the cards will be in the continuing rounds of the game, and how likely it will be that the opponent will counteract the play. In that decision, the player must also judge how much mana to leave free for other possible plays, since it is possible in Magic to play cards during your opponent's turn. The ability to budget oneself is crucial among the skills of a Magic player.
Games are developmental.
At it's absolute minimum, a person playing an RPG must at least read enough information to be able to create a character. It helps a lot if some of the basic facts are memorized, as well. All of this reading and rote memorization is exercise for the mind. RPGs can also involve a bit of writing to go along with all of the reading. Many players write their own character history and background, to help flesh out the persona that they are portraying.