How Sgriffle works

Scrabble, except the only playable words are names: every surname in the 2000 US Census held by at least 1,000 people, plus every first name the Social Security Administration has recorded for at least 1,000 babies since 1880 — 31,918 names in all. Smith counts, Li counts, Antonacci counts, Brunilda counts. "Table" does not.

17×17 board, 9 tiles on your rack, 125 tiles in the bag (2 blanks). No centre square: the first name goes anywhere, at least two letters. After that, every play must touch the names already down, and every run of letters it makes must be a name.

First turn is up for grabs. In a shared game nobody goes first by default — whoever lays down a name first takes the first turn, and the other player goes next.

Tap a tile then a square, or drag it there; drag tiles within the rack to rearrange them. You can lay tiles out on the board while you wait for your turn — only the play button waits. If the other player covers one of your squares, that tile hops back to your rack.

Build-off double. Extend a name already on the board — add letters to either end, or bridge two — and the new, longer name scores double. (Any name you form that contains two or more old tiles counts.)

Bonus squares are shuffled every game, chess960-style: the game number sets the layout (mirrored four ways). double letter · triple letter · double name · triple name. Bonus squares count only for the tiles you just placed.

All nine tiles in one go: +75. You can exchange tiles instead of playing while the bag has at least nine left (that uses your turn). The game ends when the bag is empty and someone has played their last tile (they collect the value of the opponent's rack; the other subtracts it), or after six passes in a row.

Letter values, by how common each letter is in American surnames (edited by hand where it felt right):

Not sure a name counts? The is it a name? box under the board checks the list — a yes or a no, nothing more. Invalid plays simply bounce — there's no challenging. Play from different phones (make a game and send the link), on one phone, or against the computer: hard always takes its best-scoring play, normal picks from its top six, easy plays from the weaker half of what it sees.