Level 1 is the first level in the Ever-Expanding Bunker. It houses important characters such as the IT staff, the Elite Guards and The Computer. All of The Computer's operations are devised and commanded from an unknown location in Level 1. Many of the IT staff have never left Level 1, including the Head of the IT Department who resides exclusively on Level 1. Likely due to security reasons, Level 1 is only accessible to Level 1 residents. Many residents of Level 1 work on maintaining the Computer.
Residents on Level 1 often hear terrifying noises coming from above the bunker. A faint clanging can be heard from the airlocks which the computer explains as the sound of machinery. The Computer also wipes the memories of residents on this level routinely. When the escaped manage to get through the airlocks, several residents saw a glimpse of the surface. Their memories were wiped immediately.
Level 1 is broken into different sections. Sector One is off limits to everybody but those who are approved by The Computer. Sector Two provides oxygen and power to the entirety of the bunker, while exhuming waste products to the surface above. Sector Three is home to the grand reserve where all of the bunker's ration credits are printed and reserved for later distribution. Sector Four is living quarters for residents of Level 1. There is a final sector, however it is unsure what it is used for.
In the DOTC canon, it is revealed that the Level 1 residents were the first to escape the bunker. They then proceeded to build snowmen and had fun in their new environment.