Build Your Own HTML Chess Game with JavaScript: A Step-by-Step Guide

This guide walks you through the process of creating a basic chess game using HTML, CSS, and JavaScript. We'll be using the popular chessboard.js library to handle the board and pieces.

Setting Up the Chessboard

First, we need to create a visual representation of the chessboard using HTML and CSS. Here's the code for the board structure:

<!DOCTYPE html>
<html>
<head>
	<title>Chess Game</title>
	<style>
		.board {
			display: flex;
			flex-wrap: wrap;
			width: 400px;
			height: 400px;
			border: 2px solid black;
			box-sizing: border-box;
		}
		.square {
			width: 50px;
			height: 50px;
			display: flex;
			align-items: center;
			justify-content: center;
			font-size: 40px;
			box-sizing: border-box;
		}
		.black {
			background-color: #8B4513;
			color: white;
		}
		.white {
			background-color: #FFEBCD;
			color: black;
		}
	</style>
</head>
<body>
	<div class="board">
		<div class="square white">♜</div>
		<div class="square black">♞</div>
		<div class="square white">♝</div>
		<div class="square black">♛</div>
		<div class="square white">♚</div>
		<div class="square black">♝</div>
		<div class="square white">♞</div>
		<div class="square black">♜</div>
		<div class="square black">♙</div>
		<div class="square white">♙</div>
		<div class="square black">♙</div>
		<div class="square white">♙</div>
		<div class="square black">♙</div>
		<div class="square white">♙</div>
		<div class="square black">♙</div>
		<div class="square white">♖</div>
		<div class="square black">♘</div>
		<div class="square white">♗</div>
		<div class="square black">♕</div>
		<div class="square white">♔</div>
		<div class="square black">♗</div>
		<div class="square white">♘</div>
		<div class="square black">♖</div>
	</div>
</body>
</html>

Adding Game Logic with JavaScript and chessboard.js

Now let's incorporate JavaScript and chessboard.js to make the chessboard interactive and implement the game logic. Here's the code with the necessary additions:

<!DOCTYPE html>
<html>
<head>
	<title>Chess Game</title>
	<style>
		.board {
			display: flex;
			flex-wrap: wrap;
			width: 400px;
			height: 400px;
			border: 2px solid black;
			box-sizing: border-box;
		}
		.square {
			width: 50px;
			height: 50px;
			display: flex;
			align-items: center;
			justify-content: center;
			font-size: 40px;
			box-sizing: border-box;
		}
		.black {
			background-color: #8B4513;
			color: white;
		}
		.white {
			background-color: #FFEBCD;
			color: black;
		}
	</style>
</head>
<body>
	<div id="board" class="board"></div>
	<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
	<script src="https://unpkg.com/@chrisoakman/chessboardjs@1.0.0/dist/chessboard-1.0.0.min.js"></script>
	<script>
		var board = Chessboard('board', {
			draggable: true,
			position: 'start',
		});

		var game = new Chess();

		function onDrop(source, target) {
			var move = game.move({
				from: source,
				to: target,
				promotion: 'q'
			});

			if (move === null) {
				return 'snapback';
			}
		}

		board.on('drop', onDrop);
	</script>
</body>
</html>

Explanation:

Include chessboard.js: We include the chessboard.js library from the unpkg CDN. This library provides the visual representation and basic functionality for the chessboard.
Create the board: The line var board = Chessboard('board', ...); creates the interactive chessboard using the Chessboard function. We specify the element 'board' as the container and set draggable: true to allow pieces to be moved. position: 'start' sets the initial board position to the standard starting setup.
Game Logic: We create a new Chess object from the chess.js library to handle the rules and logic of the chess game.
onDrop Function: This function is triggered when a piece is dropped on the board. It takes the source and target squares as input and attempts to make a move using game.move(). If the move is valid, it's applied to the game state. If the move is invalid (e.g., illegal move), 'snapback' is returned, causing the piece to snap back to its original position.
Event Listener: We use board.on('drop', onDrop); to attach the onDrop function to the 'drop' event of the chessboard. This ensures the onDrop function is executed whenever a piece is moved and dropped.

Conclusion

This example provides a foundational chess game that you can build upon. By adding more JavaScript logic, you can implement features such as:

Game Over Detection: Detect checkmate or stalemate conditions to determine the winner.
Move Validation: Enforce chess rules to prevent illegal moves.
Piece Promotion: Implement promotion of pawns when they reach the other side of the board.
UI Enhancements: Add elements like turn indicators, move history, or a timer to enrich the user interface.

With this framework, you can create a more sophisticated chess game and explore other game development concepts using JavaScript and HTML.

Build Your Own HTML Chess Game with JavaScript: A Step-by-Step Guide