Some useless data on Doom 2's new linedef actions

[EANB]

Doom 2 added 38 new linedef actions for level designers to use, and I would say many of them are important for giving Doom 2 its 'feel'. The new 'fast' or 'blazing' doors and lifts help to increase the speed of the game compared to its predecessor and amplify the difficulty of many traps. I was curious of just how often these new actions were used throughout the game and decided to waste a few hours of my Saturday writing this up. Maybe this has been done before, but I couldn't find it all in one place.

 

If you're unfamiliar with map editing, 'wr' means walkover repeatable, 'w1' means a walkover action that can only happen once, 'sr' means a repeatable switch, etc. 

 

First, we have the new linedef actions that went completely unused for whatever reason:

 

107 wr door close fast
108 w1 door open wait close fast
111 s1 door open wait close fast
113 s1 door close fast
121 w1 lift fast
122 s1 lift fast
128 wr floor to higher adjacent floor
129 wr floor to higher floor fast
130 w1 floor to higher floor fast
132 sr floor to higher floor fast
133 s1 door blue open stay fast

 

Next we have the actions that were used only in one map. Can you remember where?

99 sr door blue open stay fast - only in Map 4
100 w1 stairs raise by 16 - only in Map 9
110 w1 door close fast - only in Map 27
116 sr door close fast - only in Map 26
124 w1 exit secret - only in Map 15
125 w1 teleport monsters - only in Map 8
131 s1 floor to higher floor fast - only in Map 29
134 sr door red open stay fast - only in Map 4
135 s1 door red open stay fast - only in Map 2
137 s1 door yellow open stay fast - only in Map 15
140 s1 floor up 512 - only in Map 30
141 w1 crusher silent - only in Map 4

 

Now we have the actions that were only used in 2 maps

 

127 s1 stairs raise by 16 - Map 15, 21
136 sr door yellow fast - Map 4, 6
138 sr light 255 - Map 4, 28
139 sr light 35 - Map 4, 28

 

3 maps:

 

106 wr door open stay fast - Map 5, 15, 16
112 s1 door close fast - Map 9, 17, 27

Now we have the more common/useful actions.

 

105 wr door open wait close fast - used in 6 maps
109 w1 door open stay fast - used in 16 maps
114  sr door fast - used in 10 maps
115  sr door open stay fast - used in 4 maps
117 dr door open wait close fast - used in 12 maps
118 d1 door open wait close fast - used in 4 maps
119 w1 floor to higher adjacent floor - used in 5 maps
120 wr lift fast - used in 9 maps
123 sr lift fast - used in 13 maps 
126 wr teleport monsters only - used in 4 maps

 

Now some trivia: 

 

Maps 1, 7, 13, 18, 19, 24 and 31 don't use any of the new actions. They all happen to be Sandy maps. American McGee and Romero were seemingly more familiar or open to experimenting with the new features. American in particular loved fast doors, and his map 4 contains a bunch of one or two-off gimmicks such as the light level changes, and silent crushers acting as the window shutters. 

 

^{*apologies for any minor errors in this post. It's possible I glossed over some actions somewhere}

[andrewj]

2 hours ago, EANB said:

American McGee and Romero were seemingly more familiar or open to experimenting with the new features.

I think it is much more likely that the mappers asked the coders to implement particular features that they wanted or needed.

 

It's interesting that quite a few new linedef types went unused, I would guess that the coders implemented several variations at once, e.g. all the W1, WR, S1, SR activations for a particular thing (fast lift, fast door, etc), and some of those went unused -- non-repeatable doors for example are less useful than repeatable ones.

[EANB]

That's true, Romero said he was the one who programmed the editor, so it makes sense that he would create actions he needed for a specific scenario, while also creating some actions because he thought they night have some use eventually. 

[Jon]

9 hours ago, EANB said:

That's true, Romero said he was the one who programmed the editor, so it makes sense that he would create actions he needed for a specific scenario, while also creating some actions because he thought they night have some use eventually. 

The line actions aren’t implemented in the editor though, they’re in the engine. The editor just has a table of actions to numbers and labels the lines with a number. 

[Gez]

Romero also had access to the engine's source code, though, and I'm pretty sure there's an interview of him somewhere where he said he wrote the line and sector actions and just added whatever he needed when he wanted to get a new effect in a map, like the chainsaw donut in E1M2.