Othello / Reversi

01Discover the game

Othello is a placement duel where the pawns change sides without leaving the board. Each time, you put a disc and flip the opposing discs that you frame. A largely black position can turn white a few strokes later. What matters is not having the most discs in the middle of the game, but at its end.

The overall difficulty is difficult, because anticipating mobility, edges and last moves requires practice. The name Reversi also refers to this family of games. Here we keep the initial position and standard rules of Othello published by the World Othello Federation, and not a variant where we start by freely placing the first four discs.

02Equipment

It takes a tray of 8 boxes out of 8, 64 boxes, and 64 discs with two sides: one black face and one white face. Players do not have each of the different pawns: a disc turns black or white depending on the visible face. For example, columns range from A to H and rows from 1 to 8.

A well-readable gridded tray is enough. Reserves are used to place new disks; if one is empty, take a disk from the other reserve. No card, dice and separate scoreboard are required. The final number of disks can be noted to compare multiple parts without changing the winning rules.

03The goal

In the end, have more discs of your color than the opponent. A tie gives a zero part. Returning a lot of records in one stroke seems attractive, but can offer good boxes to the other side. The value of one stroke depends mainly on the answers it allows.

04Preparing the game

Place four discs in the center: White in D4 and E5, Black in E4 and D5. Decide who plays Black; Black always starts. Keep these coordinates fixed in all the drawings. The two Whites and the two Blacks thus touch diagonally, and the other 60 cells remain empty.

Before you start, show a simple frame with three squares aligned: Black, White, empty. Black can place on this last box and turn the white from the middle. This exercise allows to distinguish a real catch from a simple neighborhood.

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05Place and return discs

A blow must return at least one opponent

In your turn, place a single disc, facing your visible color, on an empty box. It is necessary that at least one line of opposing discs, without a hole, is directly between this new pose and a disc already at your disposal. The line can be horizontal, vertical or diagonal. It is not enough to touch an opponent: it must be closed by your color at the other end.

Returns all the discs so framed on each of the eight directions concerned. It is not allowed to choose only the advantageous turns. A line stops as soon as it encounters an empty box or a disc of your own color. You can't skip a disc to yourself to go look for other opponents further.

No chain reaction

Only lines starting from the box you have just placed are examined. Discs that become of your color do not in turn trigger new turns in other directions. Discs always remain on their square: only their faces are changed.

When you have to pass

If you don't have a hit that returns at least one record, you have to pass. L-adversary replays then. He can chain several turns if you remain without a legal hit. However, if a hit exists, it is forbidden to go through tactical choice.

When neither of the two players can play, the game stops, even if the board still contains empty boxes. A full board necessarily causes this stop; this is not the only way to finish. Do not distribute extra points for empty boxes in this basic explanation: simply count the faces present.

Read the eight directions without getting lost

From the new box, check to the left, the right, the top, the bottom and the four diagonals. In each direction, start with an opposing piece; follow the line until you find your color, an empty box or the edge. Only the first situation allows the reversal. This method of verification is useful at the beginning, then quickly becomes with habit.

06Two legal blows at the start

With the set-up given, Black can start in C4. Between C4 and E4 is the white disc D4; it becomes black. There are now four black discs and one white on the set. Black hasn't won yet: almost the whole game remains to be played.

White answers C3. The diagonal C3–D4–E5 frame D4 between the new white pose and the white disk E5. White returns D4. The total becomes three discs of each color. Black disks C4, D5 and E4 are not all returned: they must be examined from C3 and a line interrupted is not enough.

In another exercise, imagine horizontally A1 black, B1 white, C1 white, D1 empty. Black that poses D1 returns B1 and C1. If C1 had been black, only the portion that goes directly from D1 would have been examined: meeting a black disk next to it does not allow to cross it to return B1.

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07Count and Victory

After two impossibility to play, counts black and white records. For example, 35 blacks and 29 whites give the victory to Black; 32–32 gives a draw. If five boxes are empty and no one can play, a score of 31 blacks against 28 whites is enough to make Black win. The number of records can therefore be less than 64.

The reserve never counts to the score. The result is decided on the board only. For revenge, exchange the colors so that each starts once. You can note both scores, but do not add a new rule of victory in the middle of a game.

08Frequent errors

• Lay without turning any opposing discs.
• Believing that a nearby disk is automatically captured.
• Return to a channel from the discs that have just changed color.
• Forget a diagonal because a horizontal line was already obvious.
• Pass voluntarily when a blow is possible.
• Stop as soon as one player can no longer play: the other can continue.

09Tips for starting

The corners are precious: a disc placed in a corner can no longer be framed and returned. Before playing near an empty corner, check if you are offering this corner to the opponent. The squares right next to the corners therefore deserve special attention.

Try to leave few good choices for the other player while keeping your own possibilities. Don't measure each shot only to the number of disks returned. After one game, replay the last four strokes of one position and see how a single forced passage can change the result.