↔️ 1D Reversi Online

2-player online 1D Reversi on a 20-square line. Flip opponent's pieces by sandwiching them—first to win 3 rounds wins!

rounds (e.g. nurse, security guard, etc.) 1 / 3

Host(Black·First player)

Guest(White·Second player)

Match starting!

treatment

Click "Create Room" to get a room code and share it with your friend
Your friend enters the code with "Join Room" to join
Host plays ⚫ (first), guest plays ⚪ (second).
Click highlighted squares to place pieces (only valid moves are available).
When you sandwich opponent's pieces between your own, they flip.
If you have no valid moves, your turn is automatically skipped.
Best of 3 rounds—the first to win 2 rounds is the champion.

What is 1D Reversi Online?

1D Reversi reimagines classic Othello on a single 20-square line instead of the traditional 8×8 board. This streamlined version preserves the elegant capture mechanic where surrounded opponent pieces flip to your color, but removes 2D positioning complexity. Games are faster and clearer in strategy, perfect for understanding flipping mechanics. First to win three rounds wins the match—creating a tournament-style format ideal for online play.

How to Use

Players alternate placing pieces on the 20-square line from opposite ends, working toward the middle. When you place a piece that traps opponent pieces between your pieces, all trapped pieces flip to your color. Captured pieces become your points. After each round, the player with more pieces wins that round. Clear the board and play up to three total rounds—first to win two rounds wins the match. Share your room code with friends; the game automatically tracks round scores and determines the match winner.

Use Cases

Speed-Based Reversi: Complete full matches in 5-10 minutes instead of hour-long 8×8 games. Learning Reversi Fundamentals: Understand piece flipping and majority control without complex 2D spatial analysis. Tournament Play: Organized best-of-three match format works perfectly for casual tournaments and organized competitions. Analyzing Dimensional Effects: Compare strategies when game space changes from 2D to 1D to understand how rules adapt.

Tips & Insights

The linear format means controlling the center creates more flip opportunities than edge placement. Unlike 2D Othello where corners are safe havens, the 1D line provides no truly secure positions—all squares can potentially be surrounded. Position momentum matters more than in traditional Reversi because you can't build defensive structures on a single line. Players often win by controlling the middle section, gradually forcing opponent pieces to edges where they become increasingly vulnerable to mass captures.

Frequently Asked Questions

What is 1D Reversi?

It's Reversi (Othello) played on a single row of 20 squares. Like standard Othello, you flip opponent's pieces by sandwiching them, but the board is one-dimensional (a single horizontal line).

What moves are valid?

You can place a piece where it will flip opponent's pieces. A valid move is one where there are one or more opponent pieces in a row between your new piece and another of your pieces.

Who plays first?

The host plays ⚫ (first), the guest plays ⚪ (second). The game starts with black and white pieces placed in the center two squares (9 and 10).

What are the win conditions?

The player with more pieces when the board fills up or neither player has valid moves wins the round. The first to win 2 out of 3 rounds is the champion.

How many rounds do we need to win the match?

First to win 3 rounds wins the overall match. Each round is a separate 20-square Reversi game, so you might adjust tactics after losing a round.

What happens when all 20 squares are filled?

The round ends and the player with more pieces of their color wins. If pieces are equal at 10 each, it's a tie round and both players start fresh in the next round.

Is there a time limit per move?

Each player has 30 seconds to make their move. This encourages quick thinking while preventing excessive analysis on the small board.

How does the 1D mechanic differ from traditional Reversi?

In 1D Reversi, pieces only flip horizontally along the line—there are no diagonal flips like in 2D. This simplifies gameplay but still requires careful planning about which pieces you'll flip.

Can I take back or change my move?

No, moves are permanent once confirmed. Plan ahead since flipping your opponent's pieces immediately changes the board state in ways you need to anticipate.

What happens if I have no valid moves available?

Your turn passes to your opponent automatically. If they also have no valid moves, the round ends immediately with whoever has more pieces on the line winning.