Mahjong Real

Tiles are stacked into a pyramid-like shape, and you can only pick up two of them if they match and neither one has a tile sitting on top of or directly beside it. That's the entire rule set, and it's the standard version most people mean when they say mahjong solitaire rather than the four-player card game sharing the name. Real plays as a plain, no-frills version of it — decent if you already know the pairing rule and just want a round without extra bells attached. If you're new to it, this is as reasonable a place as any to learn, since nothing else is competing for your attention.