SELECT game.id,npc.title,users.login FROM game INNER JOIN npc ON game.id = npc.npc_id AND game.type = 'npc' INNER JOIN users ON game.id = users.user_id AND game.type = 'user'
SELECT game.id,npc.title,users.login
FROM game
LEFT JOIN npc ON game.id = npc.npc_id AND game.type = 'npc'
LEFT JOIN users ON game.id = users.user_id AND game.type = 'user'
WHERE game.type IN('npc' , 'user')