Creating Chessboard with Javascript

You can cut down your initGame logic to just add white class when y and x are either both odd or both even. You can do this by y%2 == x%2. You won't need the extra for loop.!

function initGame(){
    for(var y = 0; y < 8; y++){
        var row = [];
        for(var x = 0; x < 8; x++){
            var cell = {};
            cell.element = document.createElement("div")
            if(y%2 ==  x%2)
            {
                cell.element.className = "field white";
            }
            else 
            {
                cell.element.className = "field black";
            }
            boardElement.appendChild(cell.element);
            row.push(cell);
        }
        board.push(row);
    }

    startGame();
}