In 2016, more than 13,400 terrorist attacks took place around the world, resulting in more than 34,000 total deaths, including more than 11,600 perpetrator deaths. This represents a 9 percent decrease in the total number of terrorist attacks, and a 10 percent decrease in the total number of deaths, in comparison to 2015. Although terrorist attacks took place in 108 countries in 2016, they were heavily concentrated geographically. The vast majority of attacks (87%) and deaths (97%) occurred in the Middle East & North Africa, South Asia, and Sub-Saharan Africa. This overview summarizes patterns of terrorism in key regions in 2016, focusing on trends over time, tactics, and perpetrators. First, however, we examine patterns of terrorist attacks carried out around the world by the Islamic State of Iraq and the Levant (ISIL), as well as ISIL-affiliated and ISIL-inspired perpetrators.