Are drifters supposed to be able to spawn in lit rooms?

[Vexxvididu]

Attached is a room in my base.  It's always lit by a lamp and a torch.  I confirmed with the /debug rooms hi command that it is counted as a room.  I've had it for several in game days but just now a surface drifter spawned in there.  I killed the drifter before thinking to screen shot it.  Is there something else I can do to prevent drifter spawns or is this likely a bug or a freak incident?

I have no mods.  I think rift activity was medium at that time.

[Thorfinn]

Lamps don't provide much light. 11 in the tile the lamp is, 10 in the next, 9 one further, etc. At light level 7, drifters can spawn. It looks well lit. It is not.

[Professor Dragon]

To add on to what Thorfinn explained.

* For beginner bases, keep the rooms a LOT smaller - only a few tiles bigger than a single oil lamp in the middle. Unless you like running around relighting torches every two days.

* Light sources on the wiki here: https://wiki.vintagestory.at/Light_sources

* For when you start serious base building with bigger rooms, I highly recommend a light level checker mod.
Yes, they may be a bit "cheaty", but honestly, not too much. You do your building, put the lights in, flick the mod on and see if there is a red square or too you missed, fix it up and turn it off again. Otherwise, you're forever counting taxi-cab square spaces to lights, and that gets old fast.
Eg Easy Light Levels  - works on the current version v1.21.5.

* Finally, there is this 10 minute (ish) video on light levels which is a pretty good overview. The  main image actually captures your situation perfectly.

 

Edited October 31, 2025 by Professor Dragon

[Vexxvididu]

1 hour ago, Professor Dragon said:

To add on to what Thorfinn explained.

* For beginner bases, keep the rooms a LOT smaller - only a few tiles bigger than a single oil lamp in the middle. Unless you like running around relighting torches every two days.

* Light sources on the wiki here: https://wiki.vintagestory.at/Light_sources

* For when you start serious base building with bigger rooms, I highly recommend a light level checker mod.
Yes, they may be a bit "cheaty", but honestly, not too much. You do your building, put the lights in, flick the mod on and see if there is a red square or too you missed, fix it up and turn it off again. Otherwise, you're forever counting taxi-cab square spaces to lights, and that gets old fast.
Eg Easy Light Levels  - works on the current version v1.21.5.

* Finally, there is this 10 minute (ish) video on light levels which is a pretty good overview. The  main image actually captures your situation perfectly.

 

Thanks everyone!  I didn't realize drifters could spawn in what still LOOKS like enough light. I actually do have some zinc so I may make a couple torch holders.

[Maelstrom]

Drifters will spawn near rifts in broad daylight.

Last night had a whole army show up hours before sundown.  After I got over my amazement I checked what the rift weatherman had to say.  "While no temporal storms are expected, the rift activity is apocalyptic out there.   Seek shelter, immediately!"   So I did.

Edited October 31, 2025 by Maelstrom

[Vexxvididu]

just as a little update, this morning before work, I made some torch holders to have permanent light in a few places.  I haven't yet downloaded a light level mod, but manually counted the blocks everywhere.  I had more zinc than I even thought I dd thanks to me overprioritizing mining, haha.