Decoder Devices

Puzzles using decoder have two elements. The first element is an encoded message. This message cannot be decoded without the second element: a decoder device.

A decoder device can depict simple cipher, which are simple to use. However, the decoders in this section are less obvious to use. It will not be immediately obvious how to apply the decoding or even realize that the device is a decoder.

	Grid Lookup Find a sequence on a map by looking up grid coordinates.
	Invisible Ink A black light reactive pen and a UV flashlight reveal hidden messages.
	Paper Segment Display A template of a seven-segment display reveals numbers in an odd pattern.