Improvised Explosives Devices (IEDs) are a lethal threat to soldiers in hostilities. Until now, their use has been characteristic of the military conflict in Iraq and Afghanistan. Currently, IEDs are also used in the war in Ukraine. Their popularity is mainly due to easy access to explosives and pyrotechnics (e.g. from unexploded bombs), and chemical reagents, as well as specialistic knowledge that can be obtained online. These factors contribute to creation of effective means of combat, capable of destroying manpower and enemy's military equipment at a minimal cost and amount of work. Currently, problem of improvised explosives is particularly serious due to the fact that virtually everyone is able to make high-energy materials at home, using commercially available chemical reagents or obtaining them from unexploded explosives, and using simple tools. The matter is further complicated by the fact that, as a result of experiments, newer and newer explosives are created in "home laboratories". Those explosives are not yet widely known and tested, which increases the risk associated with IED. In this article, explosives used by terrorist groups and amateurs of pyrotechnics have been analyzed and characterized. The problem of universal access to knowledge and materials necessary to construct explosives was also discussed.