UCDP Non-state Conflict Codebook
Version 21.1
Uppsala Conflict Data Program
Department of Peace and Conflict Research
Uppsala University

This version compiled and updated by Therese Pettersson (2021)
Replacing the earlier versions by Marie Allansson & Mihai Croicu (2017), Therése Pettersson (2014), Marcus
Nilsson & Therése Pettersson (2013), Therése Pettersson (2012), Ralph Sundberg (2010), and Joakim Kreutz &Kristine Eck (2005))

When using this data, please always cite:

Sundberg, Ralph, Kristine Eck & Joakim Kreutz (2012). Introducing the UCDP Non-State
Conflict Dataset. Journal of Peace Research 49(2):351-362.
Pettersson, Therese, Shawn Davis, Amber Deniz, Garoun Engström, Nanar Hawach, Stina
Högbladh, Margareta Sollenberg & Magnus Öberg (2021). Organized violence 1989-2020,
with a special emphasis on Syria. Journal of Peace Research 58(4).
When appropriate, also cite this codebook: Pettersson, Therese (2021) UCDP Non-state
Conflict Codebook v 21.1 (https://ucdp.uu.se/downloads/).
Always include the Version number in analyses using the dataset.

Contents
1.

Introduction ............................................................................................................................. 3

2.

Definition of Non-State conflict ............................................................................................... 4
2.1

Non-state conflict ............................................................................................................ 4

2.2

Fatality estimates .............................................................................................................. 4

2.3

External state support in non-state conflict ...................................................................... 5

3.

Variables in the Non-State conflict Dataset ............................................................................. 7

4.

Data Collection Methods ....................................................................................................... 13

5.

Version name convention ...................................................................................................... 13

6.

Format availability .................................................................................................................. 14

7.

A note on UCDP ID changes ................................................................................................. 14

8.

References ............................................................................................................................. 14

1. Introduction
This document describes the Non-State Conflict Dataset, a project within the Uppsala
Conflict Data Program (UCDP) at the Department of Peace and Conflict Research, Uppsala
University. The UCDP Non-State conflict project has been developed with support fromthe Human Security Report Project, Simon Fraser University, in Vancouver, Canada.
In the development of the definition of non-state conflict, the input from Kristine Eck, Peter
Wallensteen, Margareta Sollenberg, Lotta Themnér, Ralph Sundberg, Stina Högbladh,
Therése Pettersson and Johan Brosché, have been instrumental. The UCDP non-state
conflict project is also grateful for additional advice and feedback from Andrew Mack, Zoe
Nielsen, Ole Magnus Thiesen, and others.
Case-specific information about the cases of non-state conflict is available atwww.ucdp.uu.se. Questions regarding the definitions and the content of the dataset can bedirected to ucdp@pcr.uu.se

2. Definition of Non-State conflict
2.1

Non-state conflict

A non-state conflict is defined by the Uppsala Conflict Data Program (UCDP) as “the use ofarmed force between two organized armed groups, neither of which is the government of a state,
which results in at least 25 battle-related deaths in a year.”
The separate elements of the definition are operationalized as follows:(1) Use of armed force: the use of arms, resulting in deaths.
(1.1) Arms: any material means, e.g. manufactured weapons but also sticks, stones,
fire, water, etc.
(2) 25 deaths: a minimum of 25 battle-related deaths per year(2.1) battle-related deaths: deaths directly related to the use of armed force between
the warring groups.
(3) Organized groups: consists of either(3.1) formally organized groups: any non-governmental group of people having
announced a name for their group and using armed force against another similarly
formally organized group, or(3.2) informally organized groups: any group without an announced name, but who
uses armed force against another similarly organized group, where the violent
activity meets the following requirement:(3.2.a.) there is a clear pattern of violent incidents that are connected and inwhich both groups use armed force against the other.
(4) State: a state is(4.1) an internationally recognized sovereign government controlling a specified
territory, or(4.2) an internationally unrecognized government controlling a specified territory whosesovereignty is not disputed by another internationally recognized sovereign government
previously controlling the same territory.
(5) Government: the party controlling the capital of the state.

2.2

Fatality estimates

UCDP codes three different fatality estimates – low, best and high – based on thereliability of reports and the conflicting number of deaths that can be reported for any
violent event.


Low estimate: The UCDP Low estimate consists of the aggregated low estimates forall battle-related incidents during a year. If different reports provide different
estimates and a higher estimate is considered more reliable, the low estimate is also
reported if deemed reasonable.

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 nosuch distinction can be made, UCDP as a rule include the lower figure given.
High estimate: The UCDP High estimate consists of the aggregated high estimates
for all battle-related incidents during a year. If different reports provide different
estimates and a lower estimate is considered more or equally reliable, the highestimate is also reported if deemed reasonable. If there are incidents when there issome uncertainty about what parties have been involved, these are also included in
the high estimate.

It is the best estimate of battle-related deaths that determines whether a dyad will be
included in the UCDP Non-state Conflict data (i.e. the best estimate needs to be 25 orhigher).

2.3

External state support in non-state conflict

In some cases, external states can be involved as secondary warring parties in non-state
conflicts. Examples include the US troop support to SDF in its fight against IS in Syria, andthe UAE supporting the Forces of Hadi against the Yemeni al-Qaida affiliate AQAP. The
19.1 version of the dataset was the first to code troop support from an external state innon-state conflicts. Troop support to a non-state conflict can never be coded if the country
in question has its own incompatibility with the group, or if the country is already asecondary warring party to a state-based conflict against the same group in the same
country. Hence, state-based armed conflict trumps non-state conflict. The flowchart below
elaborates on under which circumstances an external state can be included as a secondary
warring party (SWP) in non-state conflict.

Figure 1: Secondary warring parties in non-state conflicts.

3. Variables in the Non-State conflict Dataset
Variable nameContent

Type

conflict_id

The unique identifier of the non-state conflict.

Integer

dyad_id

The unique identifier of the non-state dyad (a pair of two Integer
opposing actors).
Note that one non-state conflict has, per definition, one
and only one non-state dyad. The inclusion of both dyad
IDs and conflict IDs in the dataset is meant to allow easierintegration of this dataset with other UCDP products
such as the UCDP/PRIO Armed Conflict Dataset, theUCDP Dyadic Dataset or the UCDP GED.

org

This variable indicates the organizational level of the Integer
warring sides. The level of organization is determinedaccording to the following categories:
Organizational level 1 (formally organized groups):
Rebel groups and other organized groups that have a highenough level of organization so as to be possible toinclude in the state-based armed conflict category. These
include rebel groups with an announced name, as well as
military factions (Forces of…). This level of organization
captures fighting between highly organized rebel groups
and fatalities are recorded according to the criteria set for
battle-related deaths in the state-based conflict category.
Organizational level 2 (informally organized groups):
Groups composed of supporters and affiliates to politicalparties and candidates. These are commonly not groups
that are permanently organized for combat, but who attimes use their organizational structures for such
purposes. In addition to supporters of political parties
and candidates, included in this category is also fighting
between groups composed of supporters of otherorganizations such as the supporters of al-Ahly footballteam fighting against the supporters of al-Masry footballteam in Egypt 2012. Battle-related deaths are recorded
according to section 3.2.a of the definition of non-state
conflict.
Organizational level 3 (informally organized groups):
Groups that share a common identification along ethnic,clan, religious, national or tribal lines. These are notgroups that are permanently organized for combat, but
who at times organize themselves along said lines toengage in fighting. This level of organization capturesaspects of what is commonly referred to as ‘communal
conflicts’, in that conflict stands along lines of communal

identity. Battle-related deaths are recorded according tosection 3.2.a of the definition of non-state conflict.
side_a_name

The party that constitute Side A in the conflict. For each String
conflict the parties are listed in alphabetical order, using
the latest known names of the parties involved.
Comma separated if multiple.

side_a_name_fulltext

The full original name of the actor, in English.

Stringside_a_name_mothertongue

The full original name of the actor, in mother tongue.

Stringside_a_id

The unique identifier of the groups that make up Side A.
For conflicts with multiple actors fighting together atemporary coalition ID has been assigned.

Integer

From version 17.1 of the dataset and onwards, the ID
system for conflicts, actors and dyads changed in orderto make it unique across all UCDP core datasets and all
UCDP types of violence. To download a conversion
table containing new and old IDs, visit
http://ucdp.uu.se/downloads/.
side_a_components

For conflicts with multiple actors fighting together as a String
joint (temporary) coalition, the components of thecoalition (in the form of a string of actor IDs) are listed
here. Comma separated.

side_a_2nd

side_a_2nd lists all states that enter a non-state conflict Stringwith troops to actively support side A in the dyad. See
section 2.2 for information on under which conditions
this is applicable. This variable is not part of the API
version of the dataset.
Comma separated if multiple.

gwno_a_2nd

The Gleditsch and Ward country codes of side_a_2nd. String
This variable is not part of the API version of the dataset.
Comma separated if multiple.

side_b_name

The party that constitute Side B in the conflict. For eachconflict the parties are listed in alphabetical order, using
the latest known names of the parties involved.

StringComma separated if multiple.
side_b_name_fulltext

The full original name of the actor, in English.

Stringside_b_name_mothertongue

The full original name of the actor, in mother tongue.

Stringside_b_id

The unique identifier of the groups that make up Side B.
For conflicts with multiple actors fighting together atemporary coalition ID has been assigned.

Integer

From version 17.1 of the dataset and onwards, the ID
system for conflicts, actors and dyads changed in orderto make it unique across all UCDP core datasets and all
UCDP types of violence. To download a conversion tablecontaining
new
and
old
IDs,
visit
http://ucdp.uu.se/downloads/. .
side_b_components

For conflicts with multiple actors fighting together as a String
joint (temporary) coalition, the components of thecoalition (in the form of a string of actor IDs) are listed
here. Comma separated.

side_b_2nd

side_b_2nd lists all states that enter a non-state conflict Stringwith troops to actively support side B in the dyad. See
section 2.3 for information on under which conditions
this is applicable. This variable is not part of the API
version of the dataset.
Comma separated if multiple.

gwno_b_2nd

The Gleditsch and Ward country codes of side_b_2nd. String
This variable is not part of the API version of the dataset.
Comma separated if multiple.

ext_troop_supp

type is a binary variable that codes whether the non-state Integer
conflict received external state support in the form of
troops. If there is at least one country listed in theside_a_2nd OR side_b_2nd, this variable is coded as 1. If
not, a 0 is coded. See section 2.3 for information onunder which conditions this is applicable. This variable isnot part of the API version of the dataset.

start_date

The first time there is a recorded event in a given dyad
that results in at least one fatality. This date is the samefor all years in which the conflict has been active,
regardless of whether the conflict has been active inseveral episodes or not.

Date

(YYYY-MM-DD)

The start_date is coded as precisely as possible. For
certain conflicts we can pinpoint the start of the conflict
down to a single event, taking place on a specific day. For
other conflicts, this is not possible, due to lack of precise
information.
start_prec

The start_prec (start precision) is coded to highlight the Integerlevel of certainty for the date set in the start_datevariable.

1. Day, month and year are precisely coded; thereis good information on the event.
2. Day is assigned; month and year are precisely
coded. This precision score is assigned if the firstevent which causes at least one fatality takes
place within a period of 2-6 days.
3. Day is unknown; month (or a period of 30 days,
not necessarily a calendar month) and year are
precisely coded. The day is known to be in agiven period of 30 days. The date is set to the lastdate of the period.
4. Month is assigned, year is precisely coded. The
date is set to the last day of the assigned month.
5. Day and month are assigned, year is precisely
coded. Day and month are set as precisely as
possible. For example, if an event is known tohave taken place between March and July, thedate is set to 31 July with precision score 5.
This is an automatic aggregation from the UCDP
Georeferenced Event Dataset. For more complex
inquiries in the temporal dimension of the conflict, youare advised to use the UCDP GED.
start_date2

start_date2 gives the date, as precise as possible, when agiven episode of conflict activity reached 25 battle-related
deaths.

start_prec2

Precision scores calculated as per start_prec above

Date(YYYY-MM-DD)

IntegerThis is an automatic aggregation from the UCDP
Georeferenced Event Dataset. For more complex
inquiries in the temporal dimension of the conflict, youare advised to use the UCDP GED.
ep_endep_end is a binary variable that codes whether the Integer
conflict is inactive the following year and an episode of
the conflict thus ends. If the conflict is inactive thefollowing year(s), this variable is coded as 1. If not, a 0 iscoded. For the latest year in the dataset, it is unknown
whether the conflict will be recorded as active or inactivein the following year, and the variable is always given thecode 0.

ep_end_date

This variable is only coded in years where ep_end has thevalue 1. If a conflict year is followed by at least one yearof conflict inactivity, the ep_end_date variable lists, as
precise as possible, the last date of recorded combat.

ep_end_prec

Precision scores calculated as per start_prec above.
This is an automatic aggregation from the UCDP
Georeferenced Event Dataset. For more complex

Date(YYYY-MM-DD)

Integerinquiries in the temporal dimension of the conflict, youare advised to use the UCDP GED.
year

The year of observation (1989-2020)

Integer

best_fatality_estimate

The best fatality estimate for the given conflict-year.

IntegerThis is an automatic aggregation (summing) of all theBest figures for all incidents reported for the given
conflict-year in the UCDP Georeferenced Event
Dataset.
low_fatality_estimate

The low fatality estimate for the given conflict-year.

IntegerThis is an automatic aggregation (summing) of all the Low
figures for all incidents reported for the given conflictyear in the UCDP Georeferenced Event Dataset.
high_fatality_estimate

The high fatality estimate for the given conflict-year.

IntegerThis is an automatic aggregation (summing) of all the Highfigures for all incidents reported for the given conflictyear in the UCDP Georeferenced Event Dataset.
location

The countries where fighting took place in the conflict- Stringyear.
Comma-separated if multiple.
This variable should never be used for any geographicalor spatial analyses of conflict as the distribution ofviolence as well as the relative magnitude of violence bycountry is not captured. In effect, a country is listed here
if even one dead in the given conflict has occurred in thatcountry.
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).
Like the UCDP Non-State Conflict Dataset, GED is
global and covers the same period (1989-2020).

gwno_location

The Gleditsch and Ward code for the countries where
fighting took place in the conflict-year.
Comma-separated if multiple.
This variable should never be used for any geographicalor spatial analyses of conflict as the distribution ofviolence as well as the relative magnitude of violence bycountry is not captured. In effect, a country is listed here
if even one dead in the given conflict has occurred in thatcountry. In fact, UCDP provides much better geographic
coverage of conflict (including distribution of violence for

Stringeach conflict and each country) in the UCDP
Georeferenced Event Dataset (GED).
Like the UCDP Non-State Conflict Dataset, GED is
global and covers the same period (1989-2020).
regionThe continents (regions) where violence took place:

String

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).
versionThe version of the dataset: 21.1

Float

4. Data Collection Methods
This dataset is the result of:1.
an automatic filtering and aggregation of the UCDP Georeferenced Event
Dataset from incident/event level to the conflict/dyad-year level.
2.
information gathering and coding of a number of extra variables at theaggregate conflict or actor level (such as organization type).
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, 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 first pass.
A detailed description of the process including a detailed description of the passes and thesearch-strings employed is provided in the UCDP GED Codebook version 21.1, Section 4.

5. Version name convention
In 2017, the version name convention was changed, giving all UCDP datasets the sameversion 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 21.1 of the UCDP Non-state Conflict Dataset.
For every new release, substantial changes will be documented in a separate document.
This should be helpful to researchers trying to replicate a particular study. We
recommend that whenever this dataset 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 the year is incremented.

6. Format availability
The data is available in CSV (respecting the RFC 4180 specification), Excel (XLSX), Rdata(3.x version) 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.

7. A note on UCDP ID changes
As of version 17.1 of all UCDP datasets, the ID system for conflicts, actors and dyads waschanged in order to make them unique across all UCDP core datasets and all UCDP typesof 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 theircorresponding Gleditsch and Ward country codes (GWNo). Gleditsch and Ward country
codes for state sides/actors are provided in separate columns from their sides ID (i.e.
side_a_id is different from gwno_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 thatexternal products relying on UCDP IDs for data management tasks will have to beadapted 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/

8. 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

Pettersson, Therese, Shawn Davis, Amber Deniz, Garoun Engström, Nanar Hawach, Stina
Högbladh, Margareta Sollenberg & Magnus Öberg (2021). Organized violence 1989-2020, with a
special emphasis on Syria. Journal of Peace Research 58(4).