Huge SCP fan here who’s seen roleplay groups thick and thin from 2011 to now and followed the SCP Wiki for around just as long.
The origination of Light and Heavy Containment Zones (in rare cases, Moderate Containment Zone), as well as the construction of sites altogether, were a precedent set by SCP:CB. As groups started to advance through the years and create new sites, they started thinking of different ways to represent areas. One of the first groups to pioneer sectors was Eltork’s SCP Foundation with Area 108 and ever since, most groups adapted the sector system. It’s safe to say that group set the precedent for the use of sectors.
Sectors originate from the Secure Facilities Locations canon guide, for which sectors are represented as a section of a facility used for a specific purpose (containment, research, etc). You’ll notice that most sites use sectors to designate varying levels of SCP containment with the exception of Sector 2 which often also includes the Class D Cells area (which seemingly doubles over as a common room in regards to an observation deck or room).
You should fix yourself on the narrative of your game rather than puzzling over whether to use sectors or zones. Remember that there is no lore for SCP and SCP:CB is only one representation of how the developers envision an SCP facility to play out. The same goes with SCP roleplay groups: they are focused on recreating a certain narrative and headcanon (or canon) of how they believe SCP functions.
Frankly, it is completely your choice what you decide to do. You can use both interchangeably, or one or the other. Notice that you can make many combinations off of these terms:
- Sector I
- Light Containment Zone
- Light Containment Zone, Sector III
- Sector II, Heavy Containment Zone
Primarily, here’s something to remember: X Containment Zone typically refers to, as the name states, a section of an SCP facility dedicated to the containment of entities. However, with sectors, it allows you to designate arbitrary amounts of portions of a facility without thinking of extra names for containment zones (Light, Moderate, Heavy, Special, Biological, Artifact, …).
Once again: if you’re looking for some ideas, your best bet is to first look over the Secure Facilities Locations universe guide first and then try to make the decision yourself depending on what you feel fits best. This was linked above for your convenience.
If you are making an SCP roleplay group, choose either or weave both into your game. The majority of your playerbase will understand what exactly something means: containment zones have their intentions in the title and sectors usually refer to varying levels of danger. Even if players don’t understand, their focus is to get the most amount of entertainment and danger out of your game as possible.
If you are making an actual SCP game not tied to serious roleplay, you may want to consider being more explicit in your intentions by giving your areas a clear name and setting a fitting atmosphere to indicate that you’re in a zone where safety is increasingly uncertain at every turn. Sectors and zones will easily be understood for those who were or are involved in current SCP roleplay groups but not so much for the rest of your playerbase who may not have any knowledge on what SCP is, hence the need to expertly convey your intentions through atmosphere and word choice.