“ In this dungeon, the monsters will not be hostile unless you take something without permission. If you do take something, the monsters inside will consider it stealing and attack you.”
“ The PCs come across a wild thicket of luscious looking blackberries. They eat the berries and become drunken fools. Later they find out that the berries were part of a fae garden and were intended for fae wine. In payment for stealing the berries, the mischievious fae make life inconvenient for the PCs. Horses are untied, water skins are drained, spare clothing is drug into the water, etc.”
“ A group of wizards who will give others temporary magical powers, but the price is high and those who can't pay or won't pay get very badly hurt or even killed.”