The UCDP/PRIO Armed Conflict Dataset is a joint project between the Uppsala Conflict Data Program (UCDP) at the Department of Peace and Conflict Research, Uppsala University and the Center for the Study of Civil War at the International Peace Research Institute in Oslo (PRIO). The main unit in this dataset is an “Armed Conflict” as defined by UCDP. UCDP defines conflict as: “a contested incompatibility that concerns government and/or territory where the use of armed force between two parties, of which at least one is the government of a state, results in at least 25 battle-related deaths.” The observation (or unit) is the conflict-year. Each conflict is listed in all years where fighting in one or more dyad(s) caused at least 25 battle-related deaths. Start dates frequently refer to years prior to the first calendar year of a conflict, as the start of a conflict might be in a year with less than 25 fatalities.

Variables description:

Location - the name(s) of the country/countries whose government(s) have a primary claim to the issue in dispute. Location is defined as the government side of a conflict, and should not be interpreted as the geographical location of the conflict.

Incompatibility - a general coding of the conflict issue. The incompatibility is coded in three categories: "territory", "government", "government and territory".

Year - year of observation.

Intensity level - the intensity level in the dyad per calendar year. Two different intensity levels are coded: minor armed conflicts and wars. Minor: between 25 and 999 battle-related deaths in a given year. War: at least 1,000 battle-related deaths in a given year.

Conflict type - four different types of conflict: extra systemic, interstate, internal and internationalized internal. 1) Extrasystemic armed conflict occurs between a state and a non-state group outside its own territory. (In the COW project, extra systemic war is subdivided into colonial war and imperial war, but this distinction is not used here.) These conflicts are by definition territorial, since the government side is fighting to retain control of a territory outside the state system. 2) Interstate armed conflict occurs between two or more states. 3) Internal armed conflict occurs between the government of a state and one or more internal opposition group(s) without intervention from other states. 4) Internationalized internal armed conflict occurs between the government of a state and one or more internal opposition group(s) with intervention from other states (secondary parties) on one or both sides.

Region - identifying the region of the location. This variable groups the various conflicts into five geographical categories, dependent on the location of the conflict