Free logic puzzle games: choose the deduction

Sudoku asks which values can occupy a cell

Every cell shares a row, column, and three-by-three box. The digits 1 through 9 must appear without repetition in each. A digit absent from the row can still be ruled out by the column or box, so all three groups need to be checked before an entry is justified.

A practical first question is a group with one missing digit. If a column contains eight different digits and lacks 4, inspect the blank’s row and box as well. Earlier player entries may themselves need correction. A local conflict warning identifies a repeated value, but the absence of that warning does not certify that the full puzzle’s solution uses the digit you chose.

• Open Sudoku

Minesweeper asks what neighboring clues jointly require

Each exposed number counts mines among the touching squares, including diagonals. If a 1 already touches a mine that has been proved, its other unresolved neighbors are safe. If the supposed mine was only a guess, the later conclusion depends on an unsupported assumption.

The main game protects the first reveal and its neighbors when placing mines. That safe opening is not a promise that every Classic board has a no-guess solving route. Choose this game if you want to compare small sets of constraints and distinguish demonstrated safe squares from unresolved alternatives. Flags help record your conclusions but do not make them true automatically.

• Open Minesweeper

Nonogram asks which group placements remain possible

A row clue of 3 in five cells allows a run at positions 1–3, 2–4, or 3–5. Every placement fills the center cell, while neither edge is established yet. That shared-position argument can give you a definite square before the entire group location is known.

Clues of 1 and 2 require separate groups in that order, with an empty separator. They do not mean one group of three. Cross every row deduction with the corresponding column. Recognizing a possible picture does not override the numbers. The main compact puzzles use five-by-five grids, and their progress does not persist after the page is reloaded or closed.

• Open Nonogram

2048 asks you to predict a whole-board transition

A direction slides all tiles along that axis and combines eligible equal pairs. Newly created tiles cannot merge again during the same action. Four 2s sliding left produce two 4s before the next tile appears, not an immediate 8. The order of a row or column matters, not just its total values.

Later spawns also affect the available space. Keeping the largest tile near a corner can organize your choices, but it is not a winning rule. This makes 2048 different from solving a fixed Sudoku from its initial clues: the problem changes through both your moves and new tiles. Compare the actual transitions rather than assuming one memorized direction sequence solves every board.

• Open 2048

Pick a task rather than a general ability label

Open a game whose rules interest you, or use its longer guide for another worked example. No app, player account, or ads are required. Optional analytics remain separate from the legal moves. Local saving depends on the specific game and browser rather than on a shared account across the entire collection.

Do not compare merge points, memory attempts, and safe squares revealed as if they measured the same ability. They describe different tasks and are not an intelligence or medical assessment. You can stop after a partial deduction and return voluntarily in a permitted setting. The browser format does not bypass network restrictions, and a completed puzzle does not establish a professional or health benefit outside the game.