Uploaded March 2014 | Updated September 2026, 1 hour ago
A little demonstration of the flawed collision detection, the "blockmap bug", in DOOM, using the ZDoom port. This bug is in the original DOOM engine, but is fixed in some source ports. Info on the glitch here: doomwiki.org/wiki/Flawed_collision_detection
E3M8 from The Lost Episodes of DOOM is used as an example.
Start of video
Compatibility setting: DOOM (strict) - this makes ZDoom behave like vanilla DOOM, including the bugs.
An attempt to simply grab the berserk pack and invulnerability and use it to punch out the Spiderdemon. However, because of the collision detection bug, the Spiderdemon is almost impossible to punch. The invulnerability wears off, the bug causes most of the punch attacks to not even register, and the marine dies. Assuming one plays the level from a pistol start, they would have to continue to the rest of the level to get more powerful weapons to defeat the Spiderdemon.
0:50
ZDoom's compatibility setting is now changed to "default". This fixes many bugs with DOOM, including the blockmap bug.
The same method is used as before: Trying to Berserk-kill the Spiderdemon. This time however, since the bug is fixed, the punches actually hit the enemy, and the Spiderdemon is quickly destroyed. This completely bypasses the rest of the level. This shows how certain bugs that are fixed in source ports, can actually have a big difference in certain situations such as this one.
A little demonstration of the flawed collision detection, the "blockmap bug", in DOOM, using the ZDoom port. This bug is in the original DOOM engine, but is fixed in some source ports. Info on the glitch here: doomwiki.org/wiki/Flawed_collision_detection
E3M8 from The Lost Episodes of DOOM is used as an example.
Start of video
Compatibility setting: DOOM (strict) - this makes ZDoom behave like vanilla DOOM, including the bugs.
An attempt to simply grab the berserk pack and invulnerability and use it to punch out the Spiderdemon. However, because of the collision detection bug, the Spiderdemon is almost impossible to punch. The invulnerability wears off, the bug causes most of the punch attacks to not even register, and the marine dies. Assuming one plays the level from a pistol start, they would have to continue to the rest of the level to get more powerful weapons to defeat the Spiderdemon.
0:50
ZDoom's compatibility setting is now changed to "default". This fixes many bugs with DOOM, including the blockmap bug.
The same method is used as before: Trying to Berserk-kill the Spiderdemon. This time however, since the bug is fixed, the punches actually hit the enemy, and the Spiderdemon is quickly destroyed. This completely bypasses the rest of the level. This shows how certain bugs that are fixed in source ports, can actually have a big difference in certain situations such as this one.
