Think through the whole turn

On the first turn, Blue places two own tiles on empty cells. Nothing is removed because Red has no tiles on the board yet. The placements are separate decisions: you may use matching numbers if you have two copies, or different numbers. Your opening tiles do not have to be adjacent.

From Red’s first turn onward, the normal order is to remove one opposing tile and place two of your own. Removal is mandatory and cannot be postponed until after placement. A position that looks ready for your attack must therefore be assessed by first checking what defense the current board requires.

Removal takes a tile off the board, opens its cell and returns its number to its owner’s reserve. If Blue removes a red 6 from D4, D4 becomes empty and Red recovers a 6. Blue does not gain that tile or add it to their reserve. The reserve change benefits the owner of the removed tile.

You may immediately use the newly emptied cell for one of your placements if the game continues. For example, Blue may remove from D4 and then place a blue tile there. This is legal and sometimes useful for occupying an intersection, but attractive geometry does not justify the removal if another defense was mandatory.

If the opponent finished with any valid line, your removal must eliminate all their lines for play to continue. The check happens immediately after removal. If even one opposing line remains, the game ends in their victory and you do not place. You cannot answer by forming your own line afterward.

This priority also applies when your reserve is almost exhausted. First resolve removal and any opposing victory; then place two tiles if available, or just one if it is the last in reserve. A reduced reserve cannot rescue a lost position. Keeping this order clear prevents many calculation errors in endgames.

Even if the first placement completes a line, you must make the second. That second tile might add another line, change the intersection among several lines or prepare a continuation. Stopping your calculation after finding a good first move leaves half the turn unexplored and can hide an immediate win.

Imagine two separate groups of three own tiles that each need one tile to complete a line. If both survive your removal and you have the required copies, you can complete one with the first placement and the other with the second. Studying them separately suggests two easily broken lines; studying them together may reveal an unavoidable threat.

Before acting, mentally name three decisions: what you remove, what you place first and what you place second. Check that both placement cells are empty after removal and that the numbers are available. If the two numbers match, you need two copies; one remaining copy cannot serve both selections.

The interface lets you undo actions within the current turn. The second placement commits the turn; previous turns and finished games cannot be undone. Use undo to correct an accidental tap, but try to decide your plan before executing it. The skill to train is anticipating the final board rather than discovering it through trial and error.