Marbles

The use of these is an old chestnut, but perennially popular with thieves, not least because of their effectiveness. A small bag of marbles (a general term for small spheres of glass, metal, etc.) unleashed over a stone floor to roll around forces any pursuers to slow to half normal movement rate or be forced to make a Dexterity test. If this test is failed the pursuer slips up and has to spend a full round getting up again. Because marbles roll around a lot, a small bag (30 or so) will cover a 10' x 30' (or equivalent) area. Small stones and pebbles can only be substituted for marbles if they have been polished, filed, etc., so that they are almost perfectly round—a time-consuming business.