“ A small, primitive village has yet to discover fire, which is a good thing because there are highly flammable (but not otherwise dangerous) gasses in the air. The heroes, blissful in their ignorance, don't know that and think it a wonderful idea to show the locals open flame.”
“ Have a large room that elevates either up or down when triggering a trap. The floor can bring the players to new levels, where a mighty beast roams, or the floor flattens the players into the ceiling or drop into a pit of lava.”
“ The monarch used to have absolute powers until the disappearance of King Henry V. A 'temporary' replacement was put on the throne to hold it until King Henry returned, and he would have only one vote on the governing council of nobles and no other powers except persuasion. More then 50 years have passed since then and everyone knows King Henry is almost certainly dead-but the nobles don't want to go back under the rule of an absolute monarch, so the kingship is only 'temporary' until King Henry V returns to take back his throne.”