LineDef Types by Function | LineDef Types by Number | Special Sector Types by Function | Thing Types

LineDef Reference v3.0
by Jim Flynn

LineDef Types by Function and Number

Doors | Crushers | Ceilings | Lifts | Stairs | Floors | Lighting | Teleporters | End Level | Misc | Tags

Credits

Special thanks to Matt Fell whose The Unofficial Doom Specs provided much new information for this revision, and [which] has been invaluable to WAD writers and DOOMers all along.

Thanks to Dr Sleep (aka John W. Anderson) for providing early information on the 1.666 LineDefs and for advice and encouragement all along. If you're looking for HERETIC information you want his htlndf11.txt file.

Thanks to Neil Bonner for pointing out the 667 sector tag I was missing and thereby motivating this current revision.

Legend

Abbreviations
n. = neighbor
min = minimum
max = maximum
inc = inclusive
exc = exclusive

A * appears on the left of any description line that only works for DOOM 1.666 engine and above.

LineDef Description Headers

Example:

# is the LineDef Function Type number 0-143

u1 and u2 are the number of occurrences of a trigger in DOOM1 and DOOM2.

Trigger represents the conditions that cause the function to be activated.
The trigger symbol may start with n if the function does not require a sector tag to operate.

The basic trigger symbol letters are as follows:

S = switch/door, 1st SideDef must be used with spacebar to activate.
W = walkover, only teleport LineDefs require approach from 1st SideDef.
M = monster walkover, activated only by monster walking over line.
G = impact trigger, activated on hit: fists, chain, bullet, shell.
- = no trigger required (like animated wall).

The next letter in the trigger symbol is the repeatability of the function: 1 for once only (per LineDef) and R for repeatable. This may be - if the repeatability does not apply, as for End Level.

The final letter in the trigger symbol can be m or &. The m indicates that a monster can activate the function. The & indicates that once activated, all other functions on the sector are locked out even after the & function is completed.

Brief description attempts to state in English what the function does.

Qualifier shows which key is required, crusher attribute, texture changes.

Speed is the rough relative up/down velocity involved in the operation.

Sound is the name of the sound associated with the action.

Texture Change Descriptions

Texture changes involve copying attributes from another sector to the one that is changing. If the sector being copied is based on the line triggering the change the description is prefaced with T: to indicate a trigger model change. This means that the sector on the first SideDef of the triggering LineDef is the one copied in the change. If the sector being copied is based on the sector being changed then it is the sector that is on the other side of the lowest numbered two-sided LineDef in the changing sector. Such a change is prefaced with N, for a numeric model change.

The remainder of the texture change description lists the attributes copied. 0 means that the changing sector type is set to 0 and only the floor texture is copied. SEC means that the secret attribute of the model sector is copied. DMG means that the damage attribute of the model sector is copied. Floor textures are ALWAYS copied. Ceiling textures, lighting attributes and heights are NEVER copied.

Floor Motion Directions

Floor LineDefs described as Down to functions will move the floor at the speed indicated if the target height is lower. The height change is instantaneous if motion is in other direction. Floor LineDefs described as Up to act in a similar fashion but in the opposite direction.

Door Functions

A door function described using commas only works when the door is stable in the opposite state to the function. A door function described using slashes will work anytime to toggle the opening/closing state of the door.

LineDef Types by Function