DOOM 3: BFG Edition
59 Achievements
50-60h
Double the Fun!
Kill 2 Imps with one shotgun blast in DOOM 3, RoE, or Lost Mission
1.6%
How to unlock the Double the Fun! achievement in DOOM 3: BFG Edition - Definitive Guide
Good luck!
This achievement gave me quite a few issues. You need to weaken two imps and line them up correctly for a final shogun blast. The easiest place to do this is Chapter 2 in Administration Lobby - Alpha Labs 2. If you happen to mess up and kill one of them while weakening them, just reload your save. Here is a video to help,
Credit to R3LAPZE for the video.
Simply get two Imps (the demons you're first introduced to), line them up side by side then shoot. If you struggle to kill them both with one shot, try softening them up with your pistol, shooting an equal amount of shots on both of them. They have to be right next to each other too or it won't kill both. If you are still having trouble, try the Super shotgun instead. The Super shotgun is found in certain lockers and is Double Barrelled.
The best way to get this one done would be to find two Imps and then save your game. Then get their health down using a weaker gun such as the pistol. Once both are weakened, try and get them together at an angle that would allow your pellet spread to hit both. If you miss, simply load and try again. The Super Shotgun might be better for this as it has a wider pellet spread.