“ Temple of some malign being invites you warmly and offers help (curing,needed spell etc) for some minor sacrifice . Sacrifices must be everytime bigger to work - up to living inteligent creatures. Maybe you pay some other price,too...”
“ The creatures in this dungeon will not become hostile so long as you do not cause any trouble inside. If you provoke them though, you aggro the whole dungeon. If the players are smart, they can complete the dungeon crawl without having to fight anything.”