While most charms are designed for an individual, some are designed to ward an area. Often the enchantment on these is a stronger version than that of an individual's charm.
Area charms need to be displayed appropriately in order to evoke their magic. The charms are often hung on doors, or in doorways, though some are useful for outdoors utilization. Common area charms take the form of wreaths, horseshoes, animal horns or bones, straw forms, and even simple bundles of sticks.
Common enchantments include detecting certain creature types, warding against certain creature types, alarming an area, warding an area against general investigation or incursion, etc. Detect abilities will result in the detected individual(s) being wreathed in Faerie Fire.
Destroying the charm will end its magic, though any effect that that magic is had remains for as long as appropriate (i.e. Faerie Fire continues to glow, invisible campsites remain invisible, calmed individuals remain calm, etc.)
If found, roll on the following charts to determine it's function.
1 Detect Evil
2 Detect Fay
3 Detect Lycanthrope
4 Detect Undead
5 Calming Presence (+1 bonus to all reaction rolls)
6 Under Gloomy Leaves
7 Protection from Evil 10'
8 Protection from Good 10'
9 Protection from Normal Missiles 10'
10 Invisibility 10'
11 Roll a d10 on this chart twice
12 Roll a d10 on this chart twice, add 2 to the duration roll
1 1 hour
2 8 hours
3 24 hours
4 2 days
5 3 days
6 5 days
7 1 week
8 2 weeks
9 3 weeks
10 1 month
11 Roll a d10 on this chart, and double the resulting entry
12 Roll a d10 on this chart, and quadruple the resulting entry