Whispering Powder

Wondrous item, common

When sprinkled from its paper envelope, this fine dust covers up to four 5-foot squares and reacts audibly to friction. Any creature of Small size or larger that steps into an affected area must make a DC 14 Dexterity saving throw. On a failure, loud squeals and pops erupt with each footfall, audible up to 150 feet (subtract 10 feet for each closed door and 20 feet for each substantial wall between the area and the listener).

The creator dictates the manner of sounds produced, making custom variations available at a 20% markup. The first creature to enter an affected square sets off the alarm and renders the powder in that square inert. Otherwise, the effect lasts indefinitely.