If really id say its not very good idea, cos if someone die accidently, he wont be happy and the map will get a low rating. I've made a map (zs_mrdark_bloodforest). It has a secret door, which can be locked and unlocked. The button to lock it is in the secret room, the button to unlock is hidden. (I will tell only admins and donators where is it, Mr. Slow too). But there is a way to unlock the door so the thing that you get on a tower or something - is a minus.