UCDP Battle-related Deaths Dataset Codebook
Version 23.1
Uppsala Conflict Data Program
Department of Peace and Conflict Research
Uppsala University

This version compiled and updated by Therese Pettersson (2023)
When using this data, please always cite:
Davies, Shawn, Therese Pettersson & Magnus Öberg (2023). Organized violence 1989-2022, and thereturn of conflict between states. Journal of Peace Research 60(4).

When appropriate, also cite this codebook: Pettersson, Therese (2023) UCDP Battle-related
Deaths Dataset Codebook v 23.1 (https://ucdp.uu.se/downloads/).
Always include the Version number in analyses using the dataset.

Contents
Introduction ................................................................................................................................................... 4
Definition of Armed Conflict and Battle-related Deaths ............................................................................... 5
Battle-related Deaths................................................................................................................................. 5
Best, Low and High Estimate of Battle-related Deaths .............................................................................. 6
Variables in the Battle-related Deaths Dataset .............................................................................................. 6
Data Collection Methods ............................................................................................................................ 13
Version name convention ............................................................................................................................ 13
Format availability ........................................................................................................................................ 14
A note on UCDP ID changes ...................................................................................................................... 14
References ................................................................................................................................................... 14

Introduction
This codebook presents the variables in the UCDP Battle-related Deaths Dataset, clarifies thedefinitions and methods, and provides explanations concerning the treatment of the sources
consulted. The UCDP Battle-related Deaths Dataset project was developed with support from the
Human Security Report Project, Simon Fraser University, Vancouver, Canada.
Case-specific information about the cases of one-sided violence is available at www.ucdp.uu.se
Questions regarding the definitions and the content of the dataset can be directed to
ucdp@pcr.uu.se
There are two versions of the UCDP Battle-related Deaths Dataset (BRD), depending on theunit of analysis (resolution) employed. As such, there is:
1. a dyadic version, where each individual conflict dyad (pair of two fighting actors) has its
own individual entry in each year the conflict dyad was active;
Thus, each entry contains a single pair of opposing sides (one side A and one side B) in agiven year.
Multiple dyads may form a single conflict, as a conflict is defined by its incompatibilities.
2. a conflict version, where each individual conflict has its individual entry.
Thus, each entry contains one side A (the contested party) and one or more contesters
in a given year (each entry being one contested incompatibility).
As such, for each row in the BRD Conflict version, there are one or more rows in the BRD
Dyadic version.
If you are not certain which version of the dataset to choose, it is safer to use the dyadic version;
the conflict version is an automatic aggregation of the dyadic version that automatically aggregatesand drops information.
The definition of conflict in this dataset follows the UCDP definition of armed conflict.

Definition of Armed Conflict and Battle-related Deaths
The Uppsala Conflict Data Program (UCDP) defines an armed conflict as a contested
incompatibility that concerns government and/or territory over which the use of armed force
between two parties, of which at least one is the government of a state, has resulted in at least 25
battle-related deaths in one calendar year.
The separate elements of this definition are defined as follows.
(a) Incompatibility that concerns government and/or territory. The incompatibility must concern
government and/or territory and it refers to the stated generally incompatible positions of
the parties. An incompatibility that concerns government refers to the type of political system,
the replacement of the central government or the change of the composition of the current
government. An incompatibility that concerns territory refers to the status of a territory, forexample, the change of the state in control of a certain territory (interstate conflict),
secession or autonomy (intrastate conflict).
(b) Use of armed force. This refers to the use of arms by the military forces of the parties resulting
in at least 25 deaths in a year. Arms are defined as any material means of combat, forexample, manufactured weapons as well as sticks, stones, fire, water, and so on.
(c) Party. This refers to the government of a state or an opposition organization or alliance of
opposition organizations. The government of a state is the party controlling the capital of a state.
An opposition organization is any non-governmental group which has announced a name forthe group and its political goals and has used armed force to achieve them.
(d) State. A state is an internationally recognized sovereign government controlling a specified
territory or an internationally non-recognized government controlling a specific territory
which is not disputed by an internationally recognized sovereign government, which
previously controlled the same territory.

Battle-related Deaths
Battle-related deaths refer to those deaths caused by the warring parties that can be directly related
to combat1. This includes battlefield fighting, guerrilla activities (e.g. hit-and-run attacks/ambushes)
and all kinds of bombardments of military bases, cities and villages etc. The target for the attacks iseither the military forces or representatives for the parties, though there is often substantial
collateral damage in the form of civilians being killed in the crossfire, indiscriminate bombings, etc.
All fatalities – military as well as civilian – incurred in such situations are counted as battle-related
deaths.

1

Battle-related deaths, which concern direct deaths, are not the same as war-related deaths, which includes both direct aswell as indirect deaths due to disease and starvation, criminality, or attacks deliberately directed against civilians only (onesided violence).

Best, Low and High Estimate of Battle-related Deaths
The general rule for UCDP’s estimation of battle-related deaths is moderation. All battle-related
deaths have to be verified in one way or another, and all estimates reported are based on UCDP
expertise of each particular conflict. As a general rule, all figures are disaggregated as far as possible
and any figures that are not trustworthy are disregarded in the coding process. Due to the great
uncertainty of reports from conflict areas, the project provides three estimates concerning battlerelated deaths for each year.
(a) Best estimate. The UCDP Best estimate consist of the aggregated most reliable numbers for all
battle-related incidents during a year. If different reports provide different estimates, an examination
is made as to what source is most reliable. If no such distinction can be made, UCDP as a rule include
the lower figure given.
(b) Low estimate. The UCDP Low estimate consists of the aggregated low estimates for all battlerelated incidents during a year. If different reports provide different estimates and a higher estimate isconsidered more reliable, the low estimate is also reported if deemed reasonable.
(c) High estimate. The UCDP High estimate consists of the aggregated high estimates for all battlerelated incidents during a year as listed in UCDP GED. If different reports provide different estimatesand a lower estimate is considered more or equally reliable, the high estimate is also reported if
deemed reasonable. If there are incidents when there is some uncertainty about what parties havebeen involved, these are also included in the high estimate.
It is important to emphasize that the fatality estimates given by UCDP are based on publicly accessible
sources. Due to the lack of available information, it is possible that there are more fatalities than the UCDP
high estimate, but it is very unlikely that there is fewer than the UCDP best estimate. One important caveat
is that the precision of the numbers belies the uncertainty of the estimates; while UCDP estimates are
based on aggregated totals of all incidents recorded in our sources, we acknowledge that numerous
events are not reported in the media. Figures are revised retroactively each year as new information
becomes available.

Variables in the Battle-related Deaths Dataset
The Dyadic version of the dataset contains the following fields:
Variable nameContent

Type

conflict_id

The unique identifier of the conflict to which the dyad
corresponds, as given in the UCDP/PRIO Armed
Conflict Dataset version 23.1 and the UCDP Dyadic
Dataset version 23.1

Integer

dyad_id

The unique identifier of the dyad, as given in the
UCDP Dyadic Dataset version 23.1

Integerlocation_inc

The name of the country/countries whose
government(s) has a primary claim to the incompatibility.
If multiple countries are listed, this is comma separated.

Stringside_aThe name of the country/countries of Side A in a conflict. String
Always the government side in intrastate conflicts, as givenin the UCDP/PRIO Armed Conflict Dataset.

side_a_id

The unique identifier of the actor on side A in the dyad.
Comma separated if multiple.

Stringside_a_2nd

side_a_2nd lists all states that enter a conflict dyad withtroops to actively support side A in the dyad.
A secondary warring party on side A shares the positionin the incompatibility with Side A in the conflict.
Side_a_2nd does not need to meet the 25 battle-related
deaths criterion to be included in the dataset; an active
troop participation is enough.

StringIf multiple countries are listed, this is comma separated.
side_b

The name of the country or opposition organization in
Stringthe dyad, as given in the UCDP Dyadic Dataset.
In the dyadic version of the dataset, only one side_b exists
per entry.

side_b_id

The unique identifier of the actor on side B in the dyad.

Integer

Note that in contrast with older versions of UCDP
datasets, this variable is NO LONGER the Gleditsch andWard state identifier (GWcode or GWNo) if the conflictis interstate and Side B represents a country. Use thegwno_b variable instead.
In the dyadic version of the dataset, only one side_b_id
exists per entry.
side_b_2nd

side_b_2nd lists all states that enter a conflict dyad withtroops to actively support side B in the dyad.
A secondary warring party on side B shares the positionin the incompatibility with Side B in the conflict.
Side_b_2nd does not need to meet the 25 battle-related
deaths criterion to be included in the dataset; an active
troop participation is enough.

StringIf multiple countries are listed, this is comma separated.
incompatibility

The main conflict issue identified per the UCDP
definitions, as applied to the dyad:
1= Incompatibility about territory

Integer

2= Incompatibility about government
3= Incompatibility about government AND territory
territory_name

The name of the territory over which the conflict is fought, String
provided that the incompatibility is over territory, as givenin the UCDP/PRIO Armed Conflict Dataset.

year

The year of observation (1989-2022).

Integer

bd_bestThe UCDP Best estimate for battle-related deaths in the
dyad in the given year.

Integer

bd_low

The UCDP Low estimate for battle-related deaths in the
dyad in the given year.

Integer

bd_high

The UCDP High estimate for battle-related deaths in the
dyad in the given year.

Integer

type_of_conflict

One of the following four types of conflict that the dyad is Integer
active in:
1 = extrasystemic (between a state and a non-state groupoutside its own territory, where the government side isfighting to retain control of a territory outside the statesystem)2 = interstate (both sides are states in the Gleditsch andWard membership system).
3 = intrastate (side A is always a government; side B isalways one or more rebel groups; there is no involvementof foreign governments with troops, i.e. there is noside_a_2nd or side_b_2nd coded).
4 = internationalized intrastate (side A is always agovernment; side B is always one or more rebel
groups; there is involvement of foreign
governments with troops, i.e. there is at least ONE
side_a_2nd or side_b_2nd coded).

battle_location

The name of the country/countries in which battlerelated deaths have been recorded in this dyad-year:
battle_location is a string variable, where the different
countries are separated by a comma
WARNING: This variable SHOULD NEVER be used forany geographical or spatial analyses of conflict as the
distribution of violence as well as the relative magnitudeof violence by country is not captured. In effect a country
is listed here if even one dead in the given conflict has
occurred in that country.
In fact, UCDP provides much better geographic coverageof conflict (including distribution of violence for eachconflict and each country) in the UCDP Georeferenced
Event Dataset (GED).

StringLike UCDP BRD, GED is global and covers the same
period (1989-2022).
gwno_aThe Gleditsch and Ward country codes of side_a.
Comma separated if multiple.

Stringgwno_a_2nd

The Gleditsch and Ward country codes of side_a_2nd.
Comma separated if multiple.

Stringgwno_bThe Gleditsch and Ward country codes of side_b.
Comma separated if multiple.

Stringgwno_b_2nd

The Gleditsch and Ward country codes of side_b_2nd.
Comma separated if multiple.

Stringgwno_loc

The Gleditsch and Ward country codes of theincompatibility.
Comma separated if multiple.

Stringgwno_battle

The Gleditsch and Ward country codes of battle_location. String
Comma separated if multiple.
WARNING: This variable SHOULD NEVER be used forany geographical or spatial analyses of conflict as the
distribution of violence as well as the relative magnitude ofviolence by country is not captured. In effect a country
is listed here if even one dead in the given conflict has
occurred in that country.
In fact, UCDP provides much better geographic
coverage of conflict (including distribution of violence foreach conflict and each country) in the UCDP
Georeferenced Event Dataset (GED).

regionThe region of the incompatibility (NOT of theBattle Location):
1 = Europe (GWNo: 200-399)
2= Middle East (GWNo: 630-699)
3= Asia (GWNo: 700-999)
4= Africa (GWNo: 400-626)
5= Americas (GWNo: 2-199).

StringversionThe version of the dataset: 23.1

Float

The Conflict version of the dataset contains the following fields:
Variable nameContent

Type

conflict_id

The unique identifier of the conflict, as given in the Integer
UCDP/PRIO Armed Conflict Dataset version 23.1 andthe UCDP Dyadic Dataset version 23.1

dyad_idA string variable listing all the dyads active in the current String
conflict-year separated by commas (‘,’).

year

The year of observation (1989-2022).

location_inc

The name of the country/countries whose government(s) String
has a primary claim to the incompatibility.

Integer

If multiple countries are listed, this is comma separated.
side_aThe name of the country/countries of Side A in a conflict.
Always the government side in intrastate conflicts, as
given in the UCDP/PRIO Armed Conflict Dataset.
Comma separated if multiple.

Stringside_a_2nd

side_a_2nd lists all states that enter a conflict with troops String
to actively support side A in the dyad.
A secondary warring party on side A shares the positionin the incompatibility with Side A in the conflict.
Side_a_2nd does not need to meet the 25 battle-related
deaths criterion to be included in the dataset; an active
troop participation is enough.
Comma separated if multiple.

side_a_id

The unique identifier of the actor on side A
in the dyad.

Integerside_b

The name of the country or opposition organization(s) of
side B in a conflict, as given in the UCDP/PRIO Armed
Conflict Dataset.
Comma separated if multiple.

Stringside_b_id

The identifier of each of the actors on side B in the conflict. String
Note that in contrast with older versions of UCDP
datasets, this variable is NO LONGER the Gleditsch andWard state identifier (GWcode or GWNo) if the conflictis interstate and Side B represents a country. Use thegwno_b variable instead.
If more than one opposition organization or state is
involved in a conflict, this is a comma-separated list ofvalues.

side_b_2nd

side_b_2nd lists all states that enter a conflict dyad withtroops to actively support side B in the dyad.
A secondary warring party on side B shares the positionin the incompatibility with Side B in the conflict.
Side_b_2nd does not need to meet the 25 battle-related
deaths criterion to be included in the dataset; an active
troop participation is enough.

StringComma separated if multiple.
incompatibility

The main conflict issue identified per the UCDP definitions: Integer
1= Incompatibility about government2= Incompatibility about territory
3= Incompatibility about government AND territory

territory_name

The name of the territory over which the conflict is fought, String
provided that the incompatibility is over territory, as givenin the UCDP/PRIO Armed Conflict Dataset.

bd_bestThe UCDP Best estimate for battle-related deaths in theconflict in the given year.

Integer

bd_low

The UCDP Low estimate for battle-related deaths in theconflict in the given year.

Integer

bd_high

The UCDP High estimate for battle-related deaths in theconflict in the given year.

Integer

type_of_conflict

One of the following four types of conflict over which the Integer
dyad is fought:
1 = extrasystemic (between a state and a non-state groupoutside its own territory, where the government side isfighting to retain control of a territory outside the statesystem).
2 = interstate (both sides are states in the Gleditsch andWard membership system).
3 = intrastate (side A is always a government; side B isalways one or more rebel groups; there is no involvementof foreign governments with troops, i.e. there is noside_a_2nd or side_b_2nd coded).
4 = internationalized intrastate (side A is always agovernment; side B is always one or more rebel
groups; there is involvement of foreign
governments with troops, i.e. there is at least ONE
side_a_2nd or side_b_2nd coded).

battle_location

The name of the country/countries in which battlerelated deaths have been recorded in this conflict-year:
battle_location is a string variable, where the different
countries are separated by a comma (‘,’).

StringWARNING: This variable SHOULD NEVER be used forany geographical or spatial analyses of conflict as the
distribution of violence as well as the relative magnitudeof violence by country is not captured. In effect, a country
is listed here if even one dead in the given conflict has
occurred in that country. In fact, UCDP provides muchbetter geographic coverage of conflict (including
distribution of violence for each conflict and each country)
in the UCDP Georeferenced Event Dataset (GED).
Like UCDP BRD, GED is global and covers the same
period (1989-2022).
gwno_aThe Gleditsch and Ward country code of side_a.
Comma separated if multiple.

Stringgwno_a_2nd

The Gleditsch and Ward country codes of side_a_2nd.
Comma separated if multiple.

Stringgwno_bThe Gleditsch and Ward country codes of side_b.
Comma separated if multiple.

Stringgwno_b_2nd

The Gleditsch and Ward country codes of side_b_2nd.
Comma separated if multiple.

Stringgwno_loc

The Gleditsch and Ward country codes of theincompatibility.
Comma separated if multiple.

Stringgwno_battle

The Gleditsch and Ward country codes of battle_location. String
WARNING: This variable SHOULD NEVER be used forany geographical or spatial analyses of conflict as the
distribution of violence as well as the relative magnitude ofviolence by country is not captured. In effect a country
is listed here if even one dead in the given conflict has
occurred in that country.
In fact, UCDP provides much better geographic
coverage of conflict (including distribution of violence foreach conflict and each country) in the UCDP
Georeferenced Event Dataset (GED).

regionThe region of the incompatibility (NOT of theBattle Location):
1 = Europe (GWNo: 200-399)
2= Middle East (GWNo: 630-699)
3= Asia (GWNo: 700-999)
4= Africa (GWNo: 400-626)
5= Americas (GWNo: 2-199).

StringversionThe version of the dataset: 23.1

Float

Data Collection Methods
This dataset is the result of:
1. an automatic filtering and aggregation of the UCDP Georeferenced Event Dataset fromincident/event level to the conflict/dyad-year level.
2. an automatic join of that aggregation with dyad and conflict-year data (such as secondary
warring party support or conflict typology) from the UCDP/PRIO Armed Conflict Dataset
and the UCDP Dyadic Dataset.
The original reporting underlying the dataset is collected from three sets of sources:
1. global newswire reporting
2. global monitoring and translation of local news performed by the BBC
3. secondary sources such as local media, NGO and IGO reports, field reports, social media suchas Twitter and Telegram, books etc.
The process is done in a "two-pass" system, first by consulting newswire sources for the entire
globe then by consulting local/specialized sources based on information obtained from the firstpass.
A detailed description of the process including a detailed description of the passes and the searchstrings employed is provided in the UCDP GED Codebook version 23.1, Section 4.

Version name convention
In 2017, the version name convention was changed, giving all UCDP datasets the same version
number across the board. This was done so that users more easily can see which UCDP dataset
corresponds with which.
This codebook corresponds to Version 23.1 of the UCDP Battle-related Deaths Dataset. For
every new release, substantial changes will be documented in a separate document. This shouldbe helpful to researchers trying to replicate a particular study. We recommend that whenever thisdataset is used, the version number should be cited.
The version number is a combination of a year and a number. The year refers to when thedataset is updated with new observations. If there are changes in the data between yearly
updates, or if there are substantial changes in the structure of the dataset, the number behind theyear is incremented.

Format availability
The data is available in Excel (XLSX), CSV (respecting the RFC 4180 specification), Rdata (3.xversion) and STATA (2010 format).
The data is available for machine-to-machine interaction through a public API. Documentation for
how to use the API is available at http://ucdp.uu.se/apidocs.

A note on UCDP ID changes
In version 17.1 of all UCDP datasets, the ID system for conflicts, actors and dyads was changed inorder to make them unique across all UCDP core datasets and all UCDP types of violence. This
allows easier aggregation and disaggregation of data as well as simplify data management for users,
especially when combining multiple UCDP products together.
For example, a non-state conflict cannot have the same ID as a (different) state-based conflict or
as a case of one-sided violence (which was possible before).
Further, actor/side IDs representing a government were decoupled from their corresponding
Gleditsch and Ward country codes (GWNo). Gleditsch and Ward country codes for statesides/actors are provided in separate columns from their sides ID (i.e. side_a_id is different fromgwno_a but represents the same entity).
This means all IDs used in the dataset from version 17.1 and onwards are no longer compatible
with those in older versions of UCDP products. Further, this means that external products relying
on UCDP IDs for data management tasks will have to be adapted to work with the new ID
systems.
A conversion table between the new and old ID systems is available here:
http://ucdp.uu.se/downloads/.

References
Gleditsch, Kristian S. & Michael D. Ward. 1999. "Interstate System Membership: A Revised List of
the Independent States since 1816." International Interactions 25: 393-413
Davies, Shawn, Therese Pettersson & Magnus Öberg (2023). Organized violence 1989-2022, andthe return of conflict between states. Journal of Peace Research 60(4).