The Charleston in Mahjong Island is a passing of tiles that happens before play begins. In Mahjong Island, everyone passes 3 tiles right, then 3 across, then 3 left.
The Charleston comes from American mahjong, where players pass tiles to each other as a ritual before the first turn. Mahjong Island keeps it. Each player is dealt 13 tiles, and the dealer gets a 14th. The Charleston happens next, before anyone draws or discards.
How does the Charleston work?
The Charleston is a set of passes in a fixed order, with an optional second round. Here are the steps.
Once the Charleston is done, the dealer discards first. From then on, each turn is simple. You draw a tile from the Draw Pile, the stack of face-down tiles. Then you discard 1 tile, unless your hand is complete and you win.
Which tiles should you pass?
Pass the tiles your best hands need least. You win Mahjong Island by matching 14 tiles to one line on the Island Card, the game's own card of hands. So the Charleston is your first chance to shape your tiles toward a line.
After the deal, look at the card. Find the 2 or 3 hands your tiles are closest to. Keep the tiles those hands share. A tile that none of them uses is the easiest one to pass.
To see how hands on the card are built, read how the Island Card works. For more early choices like this one, try Mahjong Island strategy for beginners. The full turn order is in the Mahjong Island rules.