.DEF File Extension

DEF files exist as 5 different types. Please find information about each of them below.

Type 1: M.U.G.E.N Character Definition File

A DEF file stores data for characters in M.U.G.E.N, a free 2D fighting game engine. It contains the character name, version, and links to specification files used by the engine. DEF files are located ...

General Information

Title DEF File Extension
Extension .def
Full Form M.U.G.E.N Character Definition File
File Type Configuration File
Developer Elecbyte
MIME Type text/plain

File Function

Primary Function Character configuration
Additional Functions Define properties, Link resources
Features Text-based, Customizable

File Characteristics

Quality Text readability
Supports Layers N/A
Supports Transparency N/A
Editable Yes

Use Cases

Game Modding Yes
Character Customization Yes
Game Development Yes

Security and Practices

Security Risks Low
Best Practices Validate entries, Backup files

Historical/Version Information

Initial Release 1999
Latest Version Depends on M.U.G.E.N version

Associated Types

Similar Extensions .sff, .snd, .cmd, .cns, .air, .pal

Software Compatibility

Software Usage Policy OS Compatibility
M.U.G.E.N Free Windows, Linux, macOS
Fighter Factory Free Windows

Type 2: Module-Definition File

General Information

Title DEF File Extension
Extension .def
Full Form Module-Definition File
File Type Configuration File
Developer Microsoft
MIME Type text/plain

File Function

Primary Function Define exports
Additional Functions Declare segments, Assign library
Features Symbols exporting, Memory allocation

File Characteristics

Quality Text-based
Supports Layers N/A
Supports Transparency N/A
Editable Yes

Use Cases

Dynamic Linking Yes
Static Libraries No
Executable Creation Yes

Security and Practices

Security Risks Code execution
Best Practices Validate syntax, Use trusted sources

Historical/Version Information

Initial Release 1980s
Latest Version Depends on toolchain

Associated Types

Similar Extensions .dll, .lib, .exp

Software Compatibility

Software Usage Policy OS Compatibility
Microsoft Visual Studio Paid, Free Community Windows
GCC Free Multiple OS
MinGW Free Windows

Type 3: SmartWare II Data File

Learn about the .DEF file extension and associated software programs. DEF files contain character definitions for the M.U.G.E.N fighting game engine. They store the character name, version, and specif...

General Information

Title DEF File Extension
Extension .def
Full Form SmartWare II Data File
File Type Data File
Developer SmartWare Corporation
MIME Type application/octet-stream

File Function

Primary Function Store data
Additional Functions Support calculations, Reporting

File Characteristics

Quality Structured
Supports Layers No
Supports Transparency No
Editable Yes

Use Cases

Data Analysis Yes
Reporting Yes
Business Planning Yes

Security and Practices

Security Risks Data leakage
Best Practices Access controls, Backups

Historical/Version Information

Initial Release 1980s
Latest Version N/A

Associated Types

Similar Extensions .wpd, .123, .xls

Software Compatibility

Software Usage Policy OS Compatibility
SmartWare II Commercial DOS

Type 4: IOBit Malware Fighter Definitions File

The def file contains malware definitions for IObit Malware Fighter. IObit Malware Fighter detects and removes malware from PCs. The def file extension associates with this Microsoft Windows software...

General Information

Title DEF File Extension
Extension .def
Full Form IObit Malware Fighter Definitions File
File Type Data File
Developer IObit
MIME Type application/octet-stream

File Function

Primary Function Store malware definitions
Additional Functions Facilitate updates
Features Encrypted, Regularly updated

File Characteristics

Quality Highly structured
Supports Layers N/A
Supports Transparency N/A
Editable No

Use Cases

Malware Detection Yes
System Security Yes
Regular Updates Yes

Security and Practices

Security Risks Corruption, Outdated
Best Practices Regular updates, Verified sources

Historical/Version Information

Initial Release Varies
Latest Version Dependent on software updates

Associated Types

Similar Extensions .dat, .sig, .db, .cat

Software Compatibility

Software Usage Policy OS Compatibility
IObit Malware Fighter Free, Paid versions Windows

Type 5: WWE 2K18 and 2K19 PAC Pointer File

This file must be edited to load custom content. WWE 2K18 and 2K19 modders adding PAC files must add references to Chunk0.def, or the games won't load them. Other WWE 2K games don't use DEF files. You...

General Information

Title .DEF File Extension
Extension .def
Full Form PAC Pointer File
File Type Game Data File
Developer 2K Sports
MIME Type application/octet-stream

File Function

Primary Function Reference game assets
Additional Functions Map data pointers
Features Binary format

File Characteristics

Quality Game-specific
Supports Layers N/A
Supports Transparency N/A
Editable With tools

Use Cases

Game Modding Yes
Asset Management Yes

Security and Practices

Security Risks Altered gameplay
Best Practices Backup original files

Historical/Version Information

Initial Release 2017 (WWE 2K18)
Latest Version 2018 (WWE 2K19)

Associated Types

Related Extensions .pac, .arc

Software Compatibility

Software Usage Policy OS Compatibility
WWE 2K18 Game Commercial Windows, PS4, Xbox One, Nintendo Switch
WWE 2K19 Game Commercial Windows, PS4, Xbox One