$duel_user = $base -> query('SELECT * FROM `duels_users` WHERE `user` = "'.$u['id'].'"') -> fetch_assoc();
<?php
include_once ('core/base.php');
include_once ('core/func.php');
falseauth();
$header = 'Дуэли';
include_once ('core/head.php');
if($u['level'] < 10){
$_SESSION['message'] = 'Ваш уровень слишком мал';
header('Location: /');
exit;
}else{
$duel_user = $base -> query('SELECT * FROM `duels_users` WHERE `user` = "'.$u['id'].'"') ->fetch_assoc();
$duel = $base -> query('SELECT * FROM `duels` WHERE `id` = "'.$duel_user['duel'].'"') -> fetch_assoc();
$oppq = $base -> query('SELECT * FROM `duels_users` WHERE `duel` = "'.$duel['id'].'" AND `user` != "'.$u['id'].'"') -> fetch_assoc();
$opp = $base -> query('SELECT * FROM `users` WHERE `id` = "'.$oppq['user'].'"') -> fetch_assoc();
$skill = $base -> query('SELECT * FROM `users_skills` WHERE `user` = "'.$u['id'].'" AND `ident_id` = "'.$u['skill'].'"') -> fetch_assoc();
$act = fl($_GET['act']);