Linedef type

Linedefs may be assigned types in order to perform special effects. Doom includes a wide selection of linedef types used in its levels, which may also be reused by level authors. Hexen also includes some extra linedef types. Some ports also add their own linedef types.

Python code to generate and decode linedef type numbers is available.

Doom linedef types
The Unofficial Doom Specs document has comprehensive additional information about linedef types.

These lists use the following terminology:
 * trigger - walk over (one-time effect)
 * retrigger - walk over (repeating effect)
 * switch - "use" (with space bar, by default) (one-time effect)
 * button - "use" (with space bar, by default) (repeating effect)

Doors

 * 1 - Open/close door
 * 26 - Open/close door BLUE KEY
 * 28 - Open/close door RED KEY
 * 27 - Open/close door YELLOW KEY
 * 31 - Open door
 * 32 - Open door BLUE KEY
 * 33 - Open door RED KEY
 * 34 - Open door YELLOW KEY
 * 46 - Open door on gunfire
 * 117 - Open/close door turbo
 * 118 - Open door turbo
 * 4 - Trigger remote door open/close
 * 29 - Switch remote door open/close
 * 90 - Retrigger remote door open/close
 * 63 - Button remote door open/close
 * 2 - Trigger remote door open
 * 103 - Switch remote door open
 * 86 - Retrigger remote door open
 * 61 - Button remote door open
 * 3 - Trigger remote door close
 * 50 - Switch remote door close
 * 75 - Retrigger remote door close
 * 42 - Button remote door close
 * 16 - Trigger remote door close/open
 * 76 - Retrigger remote door close/open
 * 108 - Trigger remote door open/close turbo
 * 111 - Retrigger remote door open/close turbo
 * 105 - Switch remote door open/close turbo
 * 114 - Button remote door open/close turbo
 * 109 - Trigger remote door open turbo
 * 112 - Switch remote door open turbo
 * 106 - Retrigger remote door open turbo
 * 115 - Button remote door open turbo
 * 110 - Trigger remote door close turbo
 * 113 - Switch remote door close turbo
 * 107 - Retrigger remote door close turbo
 * 116 - Button remote door close turbo
 * 133 - Switch remote door open turbo BLUE KEY
 * 99 - Button remote door open turbo BLUE KEY
 * 135 - Switch remote door open turbo RED KEY
 * 134 - Button remote door open turbo RED KEY
 * 137 - Switch remote door open turbo YELLOW KEY
 * 136 - Button remote door open turbo YELLOW KEY

Elevators

 * 10 - Trigger lift
 * 21 - Switch lift
 * 88 - Retrigger lift, incl monsters
 * 62 - Button lift
 * 121 - Trigger lift turbo
 * 122 - Switch lift turbo
 * 120 - Retrigger lift turbo
 * 123 - Button lift turbo

Stairs

 * 8 - Trigger stairs
 * 7 - Switch stairs
 * 100 - Trigger stairs turbo, double height
 * 127 - Switch stairs turbo, double height

Floors

 * 119 - Trigger floor up to next higher adj floor
 * 128 - Retrigger floor up to next higher adj floor
 * 18 - Switch floor up to next higher adj floor
 * 69 - Button floor up to next higher adj floor
 * 22 - Trigger floor up to next higher adj floor, xfer texture
 * 95 - Retrigger floor up to next higher adj floor, xfer texture
 * 20 - Switch floor up to next higher adj floor, xfer texture
 * 68 - Button floor up to next higher adj floor, xfer texture
 * 47 - Gunfire floor up to next higher adj floor, xfer texture
 * 5 - Trigger floor up to lowest adj/own ceiling
 * 91 - Retrigger floor up to lowest adj/own ceiling
 * 101 - Switch floor up to lowest adj/own ceiling
 * 64 - Button floor up to lowest adj/own ceiling
 * 24 - Gunfire floor up to lowest adj/own ceiling
 * 130 - Trigger floor up turbo to next higher adj floor
 * 131 - Switch floor up turbo to next higher adj floor
 * 129 - Retrigger floor up turbo to next higher adj floor
 * 132 - Button floor up turbo to next higher adj floor
 * 56 - Trigger floor up to lowest adj/own ceiling - 8, crush
 * 94 - Retrigger floor up to lowest adj/own ceiling - 8, crush
 * 55 - Switch floor up to lowest adj/own ceiling - 8, crush
 * 65 - Button floor up to lowest adj/own ceiling - 8, crush
 * 58 - Trigger floor up 24
 * 92 - Retrigger floor up 24
 * 15 - Switch floor up 24, xfer texture
 * 66 - Button floor up 24, xfer texture
 * 59 - Trigger floor up 24, xfer texture + type
 * 93 - Retrigger floor up 24, xfer texture + type
 * 14 - Switch floor up 32, xfer texture, zero type
 * 67 - Button floor up 32, xfer texture, zero type
 * 140 - Switch floor up 512
 * 30 - Trigger floor up to shortest lower texture
 * 96 - Retrigger floor up to shortest lower texture
 * 38 - Trigger floor down to lowest adj floor
 * 23 - Switch floor down to lowest adj floor
 * 82 - Retrigger floor down to lowest adj floor
 * 60 - Button floor down to lowest adj floor
 * 37 - Trigger floor down to lowest adj floor, xfer texture + type from adj
 * 84 - Retrigger floor down to lowest adj floor, xfer texture + type from adj
 * 19 - Trigger floor down to highest adj floor
 * 102 - Switch floor down to highest adj floor
 * 83 - Retrigger floor down to highest adj floor
 * 45 - Button floor down to highest adj floor
 * 36 - Trigger floor down fast to highest adj floor + 8
 * 71 - Switch floor down fast to highest adj floor + 8
 * 98 - Retrigger floor down fast to highest adj floor + 8
 * 70 - Button floor down fast to highest adj floor + 8
 * 9 - Switch floor flatten donut, xfer texture + type from adj
 * 53 - Trigger floor start moving
 * 54 - Trigger floor stop moving
 * 87 - Retrigger floor start moving
 * 89 - Retrigger floor stop moving

Ceilings

 * 40 - Trigger ceiling up to highest adj ceiling
 * 41 - Switch ceiling down to floor
 * 43 - Button ceiling down to floor
 * 44 - Trigger ceiling down to floor + 8
 * 49 - Switch ceiling down to floor + 8
 * 72 - Retrigger ceiling down to floor + 8

Crushing Ceilings

 * 25 - Trigger ceiling start crush, slow hurt
 * 73 - Retrigger ceiling start crush, slow hurt
 * 6 - Trigger ceiling start crush, fast hurt
 * 77 - Retrigger ceiling start crush, fast hurt
 * 141 - Trigger ceiling start crush, slow hurt silent
 * 57 - Trigger ceiling stop crush
 * 74 - Retrigger ceiling stop crush

Level Exit

 * 11 - Switch exit
 * 51 - Switch exit to secret level
 * 52 - Trigger exit
 * 124 - Trigger exit to secret level

Teleport

 * 39 - Trigger teleport
 * 97 - Retrigger teleport
 * 125 - Trigger teleport, monsters only
 * 126 - Retrigger teleport, monsters only

Lighting effects

 * 35 - Trigger lights off
 * 104 - Trigger lights lowest adj
 * 12 - Trigger lights highest adj
 * 13 - Trigger lights on
 * 79 - Retrigger lights off
 * 80 - Retrigger lights highest adj
 * 81 - Retrigger lights on
 * 17 - Trigger lights blink
 * 138 - Button lights on
 * 139 - Button lights off

Scrolling walls

 * 48 - Scroll wall left

Boom Linedef Types

 * 250 - Scroll tagged ceiling
 * 251 - Scroll tagged floor
 * 252 - Carry objects on tagged floor
 * 253 - Scroll tagged floor, carry objects
 * 254 - Scroll tagged wall, same as floor/ceiling
 * 255 - Scroll wall per offsets
 * 85 - Scroll wall right
 * 196 - Button remote door close/open
 * 175 - Switch remote door close/open
 * 3C00h-4000h - generalized door
 * 3800h-3C00h - generalized locked door
 * 151 - Retrigger ceiling up to highest adj ceiling
 * 166 - Switch ceiling up to highest adj ceiling
 * 186 - Switch ceiling up to highest adj ceiling
 * 145 - Trigger ceiling down to floor
 * 152 - Retrigger ceiling down to floor
 * 167 - Switch ceiling down to floor + 8
 * 187 - Button ceiling down to floor + 8
 * 199 - Trigger ceiling down to lowest adj ceiling
 * 201 - Retrigger ceiling down to lowest adj ceiling
 * 203 - Switch ceiling down to lowest adj ceiling
 * 205 - Button ceiling down to lowest adj ceiling
 * 200 - Trigger ceiling down to highest adj floor
 * 202 - Retrigger ceiling down to highest adj floor
 * 204 - Switch ceiling down to highest adj floor
 * 206 - Button ceiling down to highest adj floor
 * 4000h-5FFFh - generalized ceiling
 * 161 - Switch floor up 24
 * 180 - Button floor up 24
 * 143 - Trigger floor up 24, xfer texture
 * 148 - Retrigger floor up 24, xfer texture
 * 160 - Switch floor up 24, xfer texture + type
 * 179 - Button floor up 24, xfer texture + type
 * 144 - Trigger floor up 32, xfer texture, zero type
 * 149 - Retrigger floor up 32, xfer texture, zero type
 * 178 - Button floor up 512
 * 142 - Trigger floor up 512
 * 147 - Retrigger floor up 512
 * 158 - Switch floor up to shortest lower texture
 * 176 - Button floor up to shortest lower texture
 * 177 - Button floor down to lowest adj floor, xfer texture + type from adj
 * 159 - Switch floor down to lowest adj floor, xfer texture + type from adj
 * 219 - Trigger floor down to next lower adj floor
 * 220 - Retrigger floor down to next lower adj floor
 * 221 - Switch floor down to next lower adj floor
 * 222 - Button floor down to next lower adj floor
 * 211 - Button floor up to ceiling instantly
 * 212 - Retrigger floor up to ceiling instantly
 * 190 - Button xfer texture + type from adj
 * 189 - Switch xfer texture + type from adj
 * 154 - Retrigger xfer texture + type from adj
 * 153 - Trigger xfer texture + type from adj
 * 78 - Button xfer texture + type
 * 241 - Switch xfer texture + type
 * 240 - Retrigger xfer texture + type
 * 239 - Trigger xfer texture + type
 * 6000h-7FFFh - generalized floor
 * 3400h-37FFh - generalized lift
 * 256 - Retrigger stairs
 * 258 - Button stairs
 * 257 - Retrigger stairs turbo, double height, crush
 * 3000h-33FFh - generalized stairs
 * 259 - Button stairs turbo, double height, crush
 * 162 - Switch floor start moving
 * 163 - Switch floor stop moving
 * 181 - Button floor start moving
 * 182 - Button floor stop moving
 * 184 - Button ceiling start crush, slow hurt
 * 164 - Switch ceiling start crush, fast hurt
 * 183 - Button ceiling start crush, fast hurt
 * 150 - Retrigger ceiling start crush, slow hurt silent
 * 165 - Switch ceiling start crush, slow hurt silent
 * 185 - Button ceiling start crush, slow hurt silent
 * 168 - Switch ceiling stop crush
 * 188 - Button ceiling stop crush
 * 2F80h-2FFFh - generalized crusher
 * This BOOM list is incomplete.