In the Survival WordPress Plugin, the score table includes a Boolean field. This field is defined as tinyint(1) in the table. However, the usage of this field is not automatically managed by a WordPress plugin.
To display a boolean value in HTML, it’s essential to convert the data.
$checked = ($score->joker==1)? "checked": '';
echo "<input type='checkbox' name='joker' id='joker' $checked>";
And to store the boolean value, a conversion of the value is needed.
$joker = (int)isset($_POST['joker'])? 1: 0;