HELP

On the “Play” tab, tap a column and the disc drops to the lowest free slot. Full columns take nothing more, and while the machine is thinking the board is locked.

As soon as four of your own discs line up — horizontally, vertically or diagonally. If the board fills up and nobody has four in a row, the game is a draw.

Easy and Medium search shallowly and blunder on purpose, Hard searches seven plies deep and without slips. Unbeatable searches iteratively as deep as it can manage in 1.4 seconds — about thirteen plies on an empty board. The level can be changed at any time, even mid-game.

Yes. On the play screen, under “Opponent”, switch to “Two players” — that starts a new game. Gold and steel then take turns on the same device. There is no hint in that mode, because both of you are looking at the same screen, and such games do not count towards the statistics.

Yes, over the net. On the play screen under “Opponent” tap “Over the net”: one side creates a game and passes on the six-character code, the other joins with it. Seat 0 opens. Only the moves travel, and such games are not counted.

“Give a hint” suggests a column and says why: an immediate win, a forced block, a double threat, a necessary sacrifice or a solid build-up. The move is only played once you tap the column yourself.

With “Show threats” switched on, a green ring marks the column where you win on the next move and a dashed red ring the column where the machine wins. The golden ring is the hint you last asked for.

Yes. “Undo” takes back your last move together with the machine's reply, so it is your turn again. While the machine is thinking the button is locked.

You do, by default. With “Machine opens” the opponent takes the first move; switching starts a new game right away.

Every finished game on this device is counted, broken down by difficulty. Abandoned games do not count, and neither do games between two players. “Reset statistics” deletes the numbers for good.

Under Settings › Appearance: system default follows the device's dark mode, light and dark apply regardless. The choice survives a restart. Next to it are ten colour schemes, including “Dynamic” with your wallpaper's colours on Android 12 and up (not on iPhone, iPad and Mac).

Under Settings › Language. System default follows the device language and otherwise falls back to English; German and English apply regardless. Switching takes effect at once and the game in progress is kept.

Yes. The move order, the difficulty and who opened are saved; on the next start the position is back. On the home screen, “Continue” takes you straight to it.

In the app, under Help › “Contact & support”, there is “Show the intro again”. It then runs through its five pages and can be skipped at any time.

Only for games against other people. The search always runs on the device. Statistics and settings stay local, no data is transmitted.

Yes, from iOS 17 and macOS 14 on. It is a native rebuild with the same rules, texts and hints. Differences: nine colour schemes instead of ten (no “Dynamic”), and statistics and settings are kept per device, not synchronised.

Yes. A net game does not care which platform each side runs on: one side creates a game and passes on the six-character code, the other joins with it. Only the moves travel, and both versions work out the same board from them.

Behind the button with three lines at the top left. The bottom bar carries Home, Play and Settings; the drawer holds all six destinations plus new game, give a hint and reset statistics.