Editing Tag 667

'''Tag 667''', closely related to [[tag 666]], is used on [[Doom II]]'s [[MAP07: Dead Simple (Doom II)|MAP07]] in conjunction with the [[arachnotron]]. This is the relevant code (from [[Doom source code files#Main files|p_enemy.c]], lines 1722-1727 in the [[Doom source code]] release):

 if (mo->type == MT_BABY)
 {
   junk.tag = 667;
   EV_DoFloor(&junk,raiseToTexture);
   return;
 }

When the last arachnotron dies, any [[sector]] tagged with the number 667 is raised up by the height of the shortest lower [[texture]] of any of that sector's [[sidedef]]s. 

Tag 667 is also used in [[Strife]]. Killing all [[crusader]]s on any map will cause all sectors tagged 667 to lower their floors to the lowest surrounding floor. This effect is used in [[MAP33: Town (Strife)|MAP33: Town]] in the demo version, in [[MAP09: Castle: Programmer's Keep (Strife)|MAP09: Castle: Programmer's Keep]] and [[MAP25: Catacombs: Ruined Temple (Strife)|MAP25: Catacombs: Ruined Temple]] in the registered version, and in [[MAP35: Factory: Production (Strife: Veteran Edition)|MAP35: Factory: Production]] in the [[Strife: Veteran Edition|Veteran Edition]]. At least one player must currently be alive for this to happen.

== Bugs ==

If one of the sidedefs of the sector with the 667 tag has the "-" empty texture for a lower texture, the height of the first dummy entry in the texture list is used. In [[DOOM2.WAD]] it is [[AASHITTY]], thus the sector is raised by 64 units. This can produce effects unexpected by the map's designer if he or she is not aware of this particular quirk of the Doom engine. 

This bug was fixed in [[Boom]], which ignores sidedefs with the "-" texture in its implementation of the "raise by shortest lower texture" function. One side effect of the change is that maps utilizing tag 667 may not work as expected in [[vanilla]]-compatible engines or emulation modes, if these maps are tested only in engines that have adopted Boom's fix. [[MAP07 (Armadosia: The Mad Corridor)|MAP07]] from [[Armadosia: The Mad Corridor]] is one notable example.

Sometimes, if the last two arachnotrons on [[MAP07: Dead Simple (Doom II)|MAP07: Dead Simple]] are killed such that the last one dies before the death animation for the first one has finished, the step to the exit switch rises twice, placing it too high for the player to step onto. The level can still be completed by [[straferunning]] to the step from one of the square metal platforms, if lowered.

This bug occurs because a monster is considered dead to the source code at the beginning of its death sequence (its health is less than or equal to zero), but {{c|A_BossDeath}} is triggered at the end. Therefore, there is a short window where an arachnotron at the end of its death sequence could erroneously be considered the last arachnotron if the 'real' last arachnotron is still in the middle of its death sequence.

In addition, if the level is played with [[respawning]] monsters enabled, either through use of a [[command line arguments|command line argument]] or during play on [[skill level|Nightmare!]] difficulty, killing every arachnotron that respawns after the whole group is killed for the first time will cause the step to rise up another time, resulting in the same effect. Unlike the above, this can be done repeatedly, which will eventually cause the step to rise up to the sky. The inner sides of the step are untextured; if the player raises the step high enough in this fashion while standing on the exit platform, they will be able to see through the newly created walls, providing a view of the courtyard while remaining hidden from the enemy.

== Demo files ==

* [[Media:Tag667bug.lmp|v1.666/PrBoom demo]] ([[:Image:Tag667bug.lmp|file info]]) showing the double-rising bug on [[MAP07: Dead Simple (Doom II)|MAP07: Dead Simple]].
* [[Media:D207667.lmp|Doom95/v1.9 demo]] ([[:Image:d207667.lmp|file info]]) showing the double-rising bug on [[MAP07: Dead Simple (Doom II)|MAP07: Dead Simple]].

== See also ==
* [[Tag 666]]
* [[Strife special tags]]

[[Category:Tags]]