$re = '/[^\[]*\[(\((?P<string>(?P<param>\%[^\%]*\%)(?P<sign>.+)(?P<condition>[^\)]+))\) \{(?P<true_string>(?P<true_output>[^\|]*)\|(?P<true_param_set>[^\}]*))\}\:\{(?P<false_string>(?P<false_output>[^\|]*)\|(?P<false_param_set>[^\}]*))\})\][^\]]*/';
$str = 'тут какой то рандомный ненужный текст [(%RANDOM[0,1]%=0) {налево|%DIRECTION%=left}:{направо|%DIRECTION%=right&%SOME_ANOTHER_PARAM%=1}] тут какой то рандомный ненужный текст';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php