Endless mode: given the fastest route between two stations — always exactly six stops (📍 to 🏁) — name the line you ride for each one, in order. Every puzzle has a number; share it and whoever opens the link gets your exact puzzle and settings.
Get a stop right and it locks in, keeping its line colour with a green ring round it. Wrong ones come back grey and you go again on whatever is still open — the yellow ring shows which stop you're filling next. Attempts are unlimited. Your score is how few you need.
Some legs share track. Out of Baker Street the Circle, Hammersmith & City and Metropolitan all count as the same leg.
Overground lines show as a double stripe, as they do on the map. Windrush red sits close to Central red, and Liberty grey close to Jubilee grey, so the stripe is what tells them apart. Turn Overground off in settings to play tube, DLR and Elizabeth line only.
Disruptions restricts puzzles to ones where a line closure is what makes the trip six stops — without it the journey would be shorter. The shut line is struck off the keypad.