|Just a curtain?|
Are you sure?
Triple post today!
In the depths of the Temple of Elemental Evil there is the Greater Temple. My friends got there with their characters after long months of adventuring (and many dead adventurers); at that time we had a monk in the group: his name was Ged.
When the characters eventually got inside the Greater Temple they were overjoyed and immediately started looking for treasure. Ged choose to inspect the area behind an innocent-looking curtain, and discovered the access to the inner chamber; he didn’t notice anything unusual, and so he joined his companions who were still plundering the temple.
After a while, their thirst for riches temporarily satisfied, the characters decided to proceed beyond the curtain, but as soon as the first of them touched it, he was forced to make multiple saves against poison to prevent his arm from rotting! The curtain was entirely composed of violet fungi! And the monk hadn’t noticed because he was immune to disease!
Both Enrico (Ged’s player) and I howled with laughter, but our friends were far from happy...