UCDP Battle-Related Deaths Dataset Codebook
Version 17.1
Uppsala Conflict Data Program (UCDP)
Department of Peace and Conflict Research, Uppsala University
This version compiled and updated by Marie Allansson and Mihai Croicu (2017)

This codebook presents the variables in the UCDP Battle-related Deaths Dataset, andclarifies the definitions and methods, and provides explanations concerning the treatmentof the sources consulted. The UCDP Battle-related Deaths Dataset project was developedwith support from the Human Security Report Project, Simon Fraser University, Vancouver,
Canada.
When using the data, please refer to it with its correct name: the UCDP Battle-related Deaths
Dataset with the correct version number, and provide the URL for the UCDP website.

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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 a given 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 aggregates and drops information.

The definition of conflict in this dataset follows the UCDP definition of armed conflict. Moreinformation about the definitions and coding rules is available in the UCDP/PRIO Armed
Conflict Dataset 1946-2016 Codebook (version 17.1)

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

ConflictID

The unique identifier of the conflict to which the dyad integer
corresponds, as given in the UCDP/PRIO Armed
Conflict Dataset version 17.1 and the UCDP Dyadic
Dataset version 17.1
In version 17.1 of the dataset, the ID system forconflicts, actors and dyads has been changed in orderto make it unique across all UCDP core datasets andall UCDP types of violence. To download a conversion
table
containing
new
and
old
IDs,
visit
http://ucdp.uu.se/downloads/.

2/18

Type

DyadID

DyadID is a the numeric ID of the dyad

integerYear

The year of observation (1989-2016)

integer

LocationInc

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

SideA

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

SideA2nd

SideA2nd lists all states that enter a conflict dyad with string
troops to actively support side A in the dyad.
A secondary warring party on side A shares the
position in the incompatibility with Side A in the conflict.
SideA2nd does not need to meet the 25 battle-related
deaths criterion to be included in the dataset; an active
troop participation is enough.

SideB

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

SideBID

Side B ID is the unique identifier of the actor on side B Integer
in the dyad.
Note that in contrast with older versions of UCDP
datasets, this variable is NO LONGER the Gleditsch
and Ward state identifier (GWcode or GWNo) if theconflict is interstate and SideBID represents a country.
Use the GWNoB variable instead.
In the dyadic version of the dataset, only one SideB
exists per entry.

SideB2nd

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SideB2nd lists all states that enter a conflict dyad with string
troops to actively support side B in the dyad. By
definition, only independent states can be a secondary
warring party in conflict. A secondary warring party onside B shares the position in the incompatibility with

Side B in the conflict. SideB2nd does not need to meetthe 25 battle-related deaths criterion to be included in
the dataset; active troop participation is enough.

Incompatibility

SideB2nd is a string variable, where the different
names are separated by a comma (‘,’).
The main conflict issue identified per the UCDP integer
definitions, as applied to the dyad:
1= Incompatibility about government.

2= Incompatibility about territory.
TerritoryName
BdBest

The name of the territory over which the conflict is string
fought, provided that the incompatibility is over territory,
as given in the UCDP/PRIO Armed Conflict Dataset.
The UCDP Best estimate for battle-related deaths in Integer
the dyad in the given year.

BdLow

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

BdHighThe UCDP High estimate for battle-related deaths in Integer
the dyad in the given year.
One of the following four types of conflict over which string
the dyad is fought:

TypeOfConflict

1 = extrasystemic

2 = interstate (both sides are states in the Gleditsch
and Ward membership system).

3 = internal (side A is always a government; side B isalways one or more rebel groups; there is no
involvement of foreign governments with troops, i.e.
there is no SideA2nd or SideB2nd coded)

4 = internationalized internal (side A is always agovernment; side B is always one or more rebel
groups; there is no involvement of foreign
governments with troops, i.e. there is at least ONE
SideA2nd or SideB2nd coded)

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BattleLocation

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

WARNING: This variable SHOULD NEVER be used
for any geographical or spatial analyses of conflictas the distribution of violence as well as the relative
magnitude of violence by country is not captured. In
effect a country is listed here if even one dead in thegiven conflict has occurred in that country.

In fact, UCDP provides much better 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 (1989-2016).
GWNoA

The Gleditsch and Ward country code of SideA.

integer

GWNoA2nd

The Gleditsch and Ward country codes of SideA2nd.

stringComma separated if multiple.
GWNoB

The Gleditsch and Ward country codes of all SidesB.

integer

GWNoB2nd

The Gleditsch and Ward country codes of SideB2nd.

stringGWNoLoc
GWNoBattle

Comma separated if multiple.
The Gleditsch and Ward country codes of the string
incompatibility.
Comma separated if multiple.
The Gleditsch and Ward country codes of string
BattleLocation.
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 of violence by country is not captured. In

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effect a country is listed here if even one dead in thegiven conflict has occurred in that country.

RegionIn fact, UCDP provides much better geographic
coverage of conflict (including distribution of violence
for each conflict and each country) in the UCDP
Georeferenced Event Dataset (GED).
The region of the incompatibility (NOT of the Battle string
Location):

1 = Europe (GWNo: 200-399),
2 = Middle East (GWNo: 630-650 and 652-699)
3 = Asia (GWNo: 700-999)
4 = Africa (GWNo: 400-626 and 651)
5 = Americas (GWNo: 2-199).
VersionThe version of the dataset: 17.1

float

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

Type

ConflictID

The unique identifier of the conflict, as given in the integer
UCDP/PRIO Armed Conflict Dataset version 17.1.
In version 17.1 of the dataset, the ID system forconflicts, actors and dyads has been changed in orderto make it unique across all UCDP core datasets andall UCDP types of violence. To download a conversion
table
containing
new
and
old
IDs,
visit
http://ucdp.uu.se/downloads/.

DyadID
Year
LocationInc

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DyadID is a string variable listing all the dyads active in string
the current conflict-year separated by commas (‘,’)
The year of observation (1989-2016)
integer
The
name
of
the
country/countries
whose string
government(s) has a primary claim to theincompatibility. If multiple countries are listed, this iscomma separated.
SideA

SideA2nd

The name of the country/countries of Side A in a string
conflict. Always the government side in intrastate
conflicts, as given in the UCDP/PRIO Armed Conflict
Dataset.
SideA2nd lists all states that enter a conflict with troops string
to actively support side A in the conflict.
A secondary warring party on side A shares the
position in the incompatibility with Side A in the conflict.
SideA2nd does not need to meet the 25 battle-related
deaths criterion to be included in the dataset; an active
troop participation is enough.

SideB

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

SideBID

Side B ID is the identifier of each of the actors on side string
B in the conflict.
Note that in contrast with older versions of UCDP
datasets, this variable is NO LONGER the Gleditsch
and Ward state identifier (GWcode or GWNo) if theconflict is interstate and SideBID represents a country.
Use the GWNoB variable instead.

SideB2nd

Incompatibility

If more than one opposition organization or state is
involved in a conflict, this is a comma-separated list ofvalues.
SideB2nd lists all states that enter a conflict with troops string
to actively support side B in the conflict. By definition,
only independent states can be a secondary warring
party in conflict. A secondary warring party on side B
shares the position in the incompatibility with Side B in
the conflict. SideB2nd does not need to meet the 25
battle-related deaths criterion to be included in thedataset; active troop participation is enough.
SideB2nd is a string variable, where the different
names are separated by a comma (‘,’).
The main conflict issue identified per the UCDP integer
definitions

1= Incompatibility about government.
2= Incompatibility about territory.
TerritoryName

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The name of the territory over which the conflict is string
fought, provided that the incompatibility is over

BdBest
BdLow
BdHighTypeOfConflict

territory, as given in the UCDP/PRIO Armed
Conflict Dataset.
The UCDP Best estimate for battle-related deathsin the conflict in the given year.
The UCDP Low estimate for battle-related deathsin the conflict in the given year.
The UCDP High estimate for battle-related deathsin the conflict in the given year.
One of the following four types of conflict:
1 = extrasystemic

Integer
Integer
Integerstring2 = interstate (both sides are states in the
Gleditsch and Ward membership system).
3 = internal (side A is always a government; side B
is always one or more rebel groups; there is no
involvement of foreign governments with troops,
i.e. there is no SideA2nd or SideB2nd coded)

BattleLocation

4 = internationalized internal (side A is always agovernment; side B is always one or more rebel
groups; there is no involvement of foreign
governments with troops, i.e. there is at least ONE
SideA2nd or SideB2nd coded)
The name of the country/countries in which battle- string
related deaths have been reported in the conflict.
BattleLocation is a string variable, where thedifferent countries are separated by a comma (‘,’).
WARNING: This variable SHOULD NEVER be
used for any geographical or spatial analysesof conflict as the distribution of violence as wellas the relative magnitude of violence by country is
not captured. In effect a country is listed here ifeven one dead in the given conflict has occurred inthat country.
In fact, UCDP provides much better geographic
coverage of conflict (including distribution ofviolence for each conflict and each country) in the
UCDP Georeferenced Event Dataset (GED).

GWNoA

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Like UCDP BRD, GED is global and covers thesame period (1989-2016).
The Gleditsch and Ward country code of SideA.
integer

GWNoA2nd
GWNoB
GWNoB2nd
GWNoLoc
GWNoBattle

The Gleditsch and Ward country codes of
SideA2nd.
Comma separated if multiple.
The Gleditsch and Ward country codes of allSidesB.
Comma separated if multiple.
The Gleditsch and Ward country codes of
SideB2nd.
Comma separated if multiple.
The Gleditsch and Ward country codes of theincompatibility.
Comma separated if multiple.
The Gleditsch and Ward country codes ofBattleLocation.

stringstringstringstringstringWARNING: This variable SHOULD NEVER be
used for any geographical or spatial analyses ofconflict as the distribution of violence as well as
the relative magnitude of violence by country is not
captured. In effect a country is listed here if evenone dead in the given conflict has occurred in thatcountry.

RegionIn fact, UCDP provides much better geographic
coverage of conflict (including distribution ofviolence for each conflict and each country) in the
UCDP Georeferenced Event Dataset (GED).
The region of the incompatibility (NOT of the Battle string
Location):
1 = Europe (GWNo: 200-399),
2 = Middle East (GWNo: 630-650 and 652-699)
3 = Asia (GWNo: 700-999)
4 = Africa (GWNo: 400-626 and 651)
5 = Americas (GWNo: 2-199).

Version

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The version of the dataset: 17.1

float

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

Type

ConflictID

The unique identifier of the conflict, as given in the integer
UCDP/PRIO Armed Conflict Dataset version 17.1.
In version 17.1 of the dataset, the ID system forconflicts, actors and dyads has been changed in orderto make it unique across all UCDP core datasets andall UCDP types of violence. To download a conversion
table
containing
new
and
old
IDs,
visit
http://ucdp.uu.se/downloads/.

DyadID
Year
LocationInc

SideA

SideA2nd

DyadID is a string variable listing all the dyads active in string
the current conflict-year separated by commas (‘,’)
The year of observation (1989-2016)
integer
The
name
of
the
country/countries
whose string
government(s) has a primary claim to theincompatibility. If multiple countries are listed, this iscomma separated.
The name of the country/countries of Side A in a string
conflict. Always the government side in intrastate
conflicts, as given in the UCDP/PRIO Armed Conflict
Dataset.
SideA2nd lists all states that enter a conflict with troops string
to actively support side A in the conflict.
A secondary warring party on side A shares the
position in the incompatibility with Side A in the conflict.
SideA2nd does not need to meet the 25 battle-related
deaths criterion to be included in the dataset; an active
troop participation is enough.

SideB

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

SideBID

Side B ID is the unique identifier of the actor on side B stringin the conflict
Note that in contrast with older versions of UCDP
datasets, this variable is NO LONGER the Gleditsch
and Ward state identifier (GWcode or GWNo) if theconflict is interstate and SideBID represents a country.
Use the GWNoB variable instead.
If more than one opposition organization or state is

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SideB2nd

Incompatibility

involved in a conflict, this is a comma-separated list ofvalues.
SideB2nd lists all states that enter a conflict with troops string
to actively support side B in the conflict . By definition,
only independent states can be a secondary warring
party in conflict. A secondary warring party on side B
shares the position in the incompatibility with Side B in
the conflict. SideB2nd does not need to meet the 25
battle-related deaths criterion to be included in thedataset; active troop participation is enough.
SideB2nd is a string variable, where the different
names are separated by a comma (‘,’).
The main conflict issue identified per the UCDP/Prio integer
definitions

1= Incompatibility about government.
2= Incompatibility about territory.
TerritoryName

BdBest

BdLow
BdHighTypeOfConflict

The name of the territory over which the conflict is string
fought, provided that the incompatibility is overterritory, as given in the UCDP/PRIO Armed
Conflict Dataset.
The UCDP Best estimate for battle-related deaths Integer
in the conflict in the given year.
Casualty estimates divided by side can beobtained from the UCDP Georeferenced Event
Dataset (GED).
The UCDP Low estimate for battle-related deaths Integer
in the conflict in the given year.
The UCDP High estimate for battle-related deaths Integer
in the conflict in the given year.
One of the following four types of conflict:string
1 = extrasystemic
2 = interstate (both sides are states in the
Gleditsch and Ward membership system).
3 = internal (side A is always a government; side B
is always one or more rebel groups; there is no
involvement of foreign governments with troops,
i.e. there is no SideA2nd or SideB2nd coded)
4 = internationalized internal (side A is always agovernment; side B is always one or more rebel
groups; there is no involvement of foreign
governments with troops, i.e. there is at least ONE

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BattleLocation

SideA2nd or SideB2nd coded)
The name of the country/countries in which battle- string
related deaths that can be related to theincompatibility have been recorded.
BattleLocation is a string variable, where thedifferent countries are separated by a comma (‘,’).
WARNING: This variable SHOULD NEVER be
used for any geographical or spatial analysesof conflict as the distribution of violence as wellas the relative magnitude of violence by country is
not captured. In effect a country is listed here ifeven one dead in the given conflict has occurred inthat country.
In fact, UCDP provides much better geographic
coverage of conflict (including distribution ofviolence for each conflict and each country) in the
UCDP Georeferenced Event Dataset (GED).

GWNoA
GWNoA2nd
GWNoB
GWNoB2nd
GWNoLoc
GWNoBattle

Like UCDP BRD, GED is global and covers thesame period (1989-2016).
The Gleditsch and Ward country code of SideA.
The Gleditsch and Ward country codes of
SideA2nd.
Comma separated if multiple.
The Gleditsch and Ward country codes of allSidesB.
Comma separated if multiple.
The Gleditsch and Ward country codes of
SideB2nd.
Comma separated if multiple.
The Gleditsch and Ward country codes of theincompatibility.
Comma separated if multiple.
The Gleditsch and Ward country codes ofBattleLocation.
WARNING: This variable SHOULD NEVER be
used for any geographical or spatial analyses ofconflict as the distribution of violence as well as
the relative magnitude of violence by country is not
captured. In effect a country is listed here if evenone dead in the given conflict has occurred in thatcountry.

12/18

integerstringstringstringstringstring

RegionIn fact, UCDP provides much better geographic
coverage of conflict (including distribution ofviolence for each conflict and each country) in the
UCDP Georeferenced Event Dataset (GED).
The region of the incompatibility (NOT of the Battle string
Location):
1 = Europe (GWNo: 200-399),
2 = Middle East (GWNo: 630-650 and 652-699)
3 = Asia (GWNo: 700-999)
4 = Africa (GWNo: 400-626 and 651)
5 = Americas (GWNo: 2-199).

VersionThe version of the dataset: 17.1

float

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. 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, books etc.

The process is done in a "two-pass" system, first by consulting newswire sources for theentire 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 17.1, Section 4.

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Further Discussion on Battle-related Deaths

Battle-related deaths refer to those deaths caused by the warring parties that can bedirectly related to combat 1. This includes traditional battlefield fighting, guerrilla activities(e.g. hit-and-run attacks/ambushes) and all kinds of bombardments of military bases, cities
and villages etc. Urban warfare (bombs, explosions, and assassinations) does not resemble
what happens on a battlefield, but such deaths are considered to be battle-related. The
target for the attacks is either 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 – incurredin such situations are counted as battle-related deaths.
Sources

The data presented by UCDP is based on information taken from a selection of publicly
available sources, printed as well as electronic. The sources include news agencies,
journals, research reports, and documents of international and multinational organizations
and NGOs. This includes documents of the warring parties (governments and opposition
organizations) when such sources are available, since they serve as a crucial complement
when identifying statements about the parties’ incompatible positions. Global, regional andcountry-specific sources are used for all countries.

Both the independence and the transparency of the sources are deemed crucial. Eachsource is judged according to the context in which it is published, that is, according to thepotential interests of the source in misrepresenting political or violent events. Since mostsources are secondary sources, UCDP attempts to trace reports back to the primary sourcein order to decide whether they are reliable. In cases of biased sources or in situations
where there is unreliable information, the events are normally only included in the highestimate.
Little information on the exact number of deaths in conflict is usually available, and media
coverage varies considerably from country to country. It is important to emphasize that thefatality estimates given by UCDP is based on publicly accessible sources. Due to the lack ofavailable information, it is possible that there are more fatalities than the UCDP highestimate, 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 the1

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
(one-sided violence).

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estimates; while UCDP estimates are based on aggregated totals of all incidents recorded inour sources, we acknowledge that numerous events are not reported in the media. Figures
are revised retroactively each year as new information becomes available.

In addition to deciding the level of reliability of available sources, the project strives to
identify the existence of censorship. Thus, other sources than regular news sources must be
used to establish what is occurring in a country. Documents and reports issued byinternational and multinational organizations and NGOs are consulted for this purpose.

Best, Low and High Estimate of Battle-related Deaths

The general rule for UCDP’s estimation of battle-related deaths is moderation. All battlerelated 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 projectprovides three estimates concerning battle-related 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
battle-related incidents during a year. If different reports provide different estimates and ahigher estimate is considered 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
battle-related incidents during a year as listed in UCDP GED. 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 is someuncertainty about what parties have been involved, these are also included in the highestimate.

Missing data problems
The missing data code is -99.

In version 17.1 there is one case of missing data when it comes to battle-related deaths,
namely the low estimate in Syria in 2014. See Themnér & Wallensteen (2014) for a morein-depth discussion on the case of Syria.

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See the discussion above for biased estimates and data collection problems.

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 will soon be available for machine-to-machine interaction through a public API as
an open beta during stage 2 of the UCDP API extension. Documentation for how to use the
API is available at http://ucdp.uu.se/apidocs.

Appendix 1 : Definition of Armed Conflict:
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 thatconcerns territory refers to the status of a territory, for example, the change of thestate 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 ofcombat, for example, 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 oralliance of opposition organizations. The government of a state is the party
controlling the capital of a state. An opposition organization is any non-

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governmental group which has announced a name for the group and its politicalgoals 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.

Appendix 2: 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 17.1 of the UCDP Battle-related Deaths Dataset. For
every new release, substantial changes will be documented in a separate document. Thisshould be helpful to researchers trying to replicate a particular study. We recommend thatwhenever 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.

Appendix 3: A note on UCDP ID changes

In version 17.1 of all UCDP datasets, the ID system for conflicts, actors and dyads has beenchanged in order to make them unique across all UCDP core datasets and all UCDP types ofviolence. This will allow 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 ID will no longer be able to have the same ID as a(different) state-based conflict ID or as a case of one-sided violence (which was possible
before).

Further, actor/side IDs representing a government have been decoupled from theircorresponding Gleditsch and Ward country codes (GWNo). This will allow, in the future, theidentification of regime changes within a country etc. Gleditsch and Ward country codes forstate sides/actors will continue to be 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 this version of the dataset are no longer compatible with those inolder versions of UCDP products. Further, this means that external products relying on

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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
Gleditsch, Nils Petter; Peter Wallensteen; Mikael Eriksson: Margareta Sollenberg & Håvard
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