This 2-foot-long metal tube has right angles at each end with mirrors inside; if you look in one end, you can see out the other end, allowing you safely peer over obstacles, around corners, or into small spaces your head wouldnt fit. When using a periscope, the end of the tube counts as a Diminutive object, making it much less likely an observed creature notices you; if you have total concealment from the creature except for the end of the periscope, use the tube’s Diminutive size modifier for your Stealth instead of your own size modifier. Distortion from the mirrors gives you a -4 penalty on Perception checks while looking through the periscope. Though the tube is fairly sturdy (hardness 5, 2 hit points), the mirrors inside are fragile (hardness 1, 1 hit point), and any damage that gets through the tube’s hardness applies to the tube and the mirrors.
Ultimate Equipment Guide II
Author Greg Lynch, J. C. Alvarez
Publisher Mongoose Publishing
Publish date 2005
The periscope is a rigid leather tube about two and a half feet long with holes cut in the sides at each end. Behind each hole is a mirror, mounted at such an angle that anyone peering into one of the holes can see, through the reflection of the mirrors, whatever is visible through the other hole. The periscope is an invaluable tool to the adventurer, allowing him to looking around a corner or over a wall without actually exposing himself to any dangers that may lie in wait. Anyone using the periscope in such a manner may retain all appropriate advantages due to cover and concealment. For example, an adventurer using the periscope to look around the corner of a dungeon passageway could retain all bonuses for full cover while examining what lies ahead. The periscope would, of course, be visible, but the adventurer himself would not be.
The periscope cannot be used by an enemy of the adventurer to target a spell at him (for example, spells like disintegrate and magic missile can be targeted at the periscope, but they will not affect the adventurer through the periscope) though he may, of course, be affected by an area-effect spell. Likewise, the individual using the periscope may not target spells through it; he must be able to directly see his target. The periscope also, obviously, renders useless any gaze attacks that are normally foiled when viewed through a reflection. While an excellent tool, the periscope is not perfect, however. Looking through a pair of small mirrors at something is no substitute for actually looking directly at it, and the user of the periscope receives a -4 penalty to all Spot skill checks when looking through the device.