What am I doing wrong when trying to set the default value for this radio button form element? $options = array(
    'yes' =&gt; t('Yes'),
    'no' =&gt; t('No'),
    'maybe' =&gt; t('Maybe'),
  );

  $form['infx2670selig_kangaroo_eating'] = array(
    '#type' =&gt; 'radios',
    '#title' =&gt; 'Would you eat a kangaroo?',
    '#default_value' =&gt; t('No'),
    '#options' =&gt; $options,
    '#required' =&gt; TRUE,
  );


I don't see what's going wrong. By default, none are selected.
The #default_value is the key in the $options array. you want:

'#default_value' =&gt; 'no',