Telegraph

The prairie is a grid of tiles, and every tile carries a length of telegraph wire — a straight, a corner, a T, or an end where a station stands — a small round node. In the middle, the big node is the telegraph office. Somebody has spun every tile. Turn them back, a quarter at a time, until the wire runs from the office to every station as one line: every wire end meeting another, nothing running off the edge, and no loop anywhere — a loop is a short, and it flickers red when you make one. Wire joined to the office lights up gold as you go, and when the last station lights, the line is up.

Every board has exactly one way to wire it, proved by two separate solvers before you see it, and none asks you to guess.

Turns and par

Each tile is some number of quarter-turns from home, and the fewest turns that solve the board — taking each tile the short way round — is its par. Every turn past par is wasted. A tap turns a tile clockwise; the Turn button switches taps to anticlockwise, so a tile three clockwise turns from home is one turn the other way. Hold a tile to pin it once you are sure — a pinned tile won't turn until you hold it again. Solving with no wasted turns is the feat the best badges ask for.

The Daily

Every day there are three new boards — an Easy, a Medium and a Hard — the same three for everybody in the world, turning over at midnight UTC. Each is a race against the clock: four minutes for the Easy, eight for the Medium, fifteen for the Hard, counting down while you play and stopping whenever you step away. Solve it in time and your time goes on the leaderboard; if the clock reaches zero, that board is a miss for the day and your streak starts again tomorrow. There are no hints on the Daily. Free play has no clock to beat and three hints a board — a hint points at a tile to turn (or at a pinned tile that is wrong); it never turns anything for you.

How the levels are graded

• Easy (5×5) falls to local reasoning alone: the border and the ends beside a tile decide which way it faces.
• Medium (7×7) needs the whole line once or twice: a turn that would close a loop, or seal a piece of wire off from the office, is wrong.
• Hard (9×9) needs that line-wide look again and again, across long runs of straights with few stations to anchor them.

Where it comes from

Telegraph is a rotation puzzle of the kind usually called Net, long a favourite of puzzle collections: a network of pipes or wires scrambled tile by tile, to be turned back into one connected tree. This one is strung across a prairie at night.

The rules in full, par and wasted turns, the levels, the skins and the badges are in the Telegraph guide.