The humble knife has been at the side of almost every sentient species since they first learned to shape tools. Used for many tasks including making shelter, preparing clothing, processing game animals and fish to religious rituals, the knife has had a place in every culture in every corner of the galaxy. Knives vary in shape, size, and construction based on the history, culture, and physiology of the species. There are almost as many types of knives as there are stars in the sky, but they share a number of features in common.
All knives have a primary blade. Some folding knives may have more than one blade, but they too have a primary blade. Typically, this blade will be made of some kind of hardened metal, although stone, bone, and antler have historically been used as well. A general-purpose knife will have a blade between ten centimeters and fifteen centimeters long, although more specialized knives such as certain chef’s knives may be longer and folding knives typically have blades shorter than ten centimeters long to increase comfort when carried in a pocket. A knife blade will have one sharpened cutting edge, usually, a plain straight edge, although some blades do incorporate partial or even full serrations.
Knives will also have a handle for the user to grip when using the blade. Most modern knives will have polymer handles, although wood, metal, and other materials are also commonly used. The handles can be brightly colored or decorated, depending on the use. Some fancier knives will be made with costly decoration of gems or precious metals and carried more as status symbols than as actual tools.
While the typical knife is not optimized for combat, as opposed to dedicated fighting knives, any knife can be used to defend oneself in a pinch. Most sentient species are quite averse to having sharp implements rending their flesh and the very act of brandishing a knife when in harm’s way can often persuade an assailant to search elsewhere for more vulnerable prey.