A Japanese war fan is a fan designed for use in warfare. Several types of war fans were used by the samurai class of feudal Japan and each had a different look and purpose.

There are three kinds of war fan:

Gunsen (軍扇) were folding fans used by the average warriors to cool themselves off. They were made of wood, bronze, brass or a similar metal for the inner spokes, and often used thin iron or other metals for the outer spokes or cover, making them lightweight but strong. Warriors would hang their fans from a variety of places, most typically from the belt or the breastplate, though the latter often impeded the use of a sword or a bow. Example: post #2540638

[[Tessen]] (鉄扇) were folding fans with outer spokes made of heavy plates of iron which were designed to look like normal, harmless folding fans or solid clubs shaped to look like a closed fan. Samurai could take these to places where swords or other overt weapons were not allowed, and some swordsmanship schools included training in the use of the tessen as a weapon. The tessen was also used for fending off knives and darts, as a throwing weapon, and as an aid in swimming. Example: post #1904493

[[Gunbai]] (Gumbai), Gunpai (Gumpai) or dansen uchiwa (軍配) were large solid open fans that could be solid iron, metal with wooden core, or solid wood, which were carried by high-ranking officers. They were used to ward off arrows, as a sunshade, and to signal to troops. Also used by scoring referees in sumo wrestling matches. Example: post #1990137
軍配 鉄扇 軍扇