How can I uncheck a required checkbox on the edit page for a given content type? I have a "required" checkbox (single on-off boolean field) which users must check to agree to the rules of the site when they post a node of a certain content type.  When users edit nodes of this content type, I would like to reset the checkbox to force them to check it again.

How can I do this in Drupal 7?
Implement hook_form_FORM_ID_alter() such that it clears the #default_value property of the widget:

function mymodule_form_node_form_alter(&amp;$form, &amp;$form_state, $form_id) {
  $node_type = 'example_type'; // TODO: change to the desired node type
  $field = 'field_example';    // TODO: change to the name of the field

  $node = $form['#node'];
  if ($node-&gt;type == $node_type) {
    $language = $form[$field]['#language'];
    $form[$field][$language]['#default_value'] = 0;
  }
}