Extends the default Advanced Custom Fields get_field function to allow options for a default value and fallback to global options value.

get-field-extended.php

<?php
if ( ! function_exists( 'get_field_ext' ) && ( function_exists( 'get_field' ) ) ) {
  /**
	 * Extends the default ACF get_field function to allow options for a default value and fallback to global option
	 *
	 * @author Gabe Shackle       	<gabe@hereswhatidid.com>
	 * @param  string $name       	Field name
	 * @param  mixed $default    	Default value if none found
	 * @param  integer $id		Post ID to check the field value of
	 * @return mixed             	Value after running checks
	 */
	function get_field_ext( $name = '', $default = null, $id = null ) {
		if ( ! empty( $id ) ) {
			if ( $result = get_field( $name, $id ) ) {
				return $result;
			}
		} else {
			if ( ( $result = get_field( $name ) ) || ( $result = get_field( $name, 'options' ) ) ) {
				return $result;
			}
		}
		return $default;
	}
}
?>