Sub-Discovery Block is a local delicacy of Fontaine that can be found in the northern parts of the region. It is an artificial component created by the Fontaine Research Institute to monitor environmental data that visually appears as a mechanical error. Sub-detection modules are used as Ascension materials for Wriothesley and possibly other Fontainean characters in the future. There are a limited number of them in the wild, so I recommend collecting them whenever you come across them.
Where to farm Subdetection Unit in Genshin Impact
The sub-detection unit looks like a mechanical error that glows blue and red, but it is still difficult to detect because it is so small. Although visually similar to a scarab, it doesn’t move or run away, so you won’t have too much trouble picking it up.
Most of the Sub-Discovery units are scattered across the northern Liffey Fontaine region, and there are not enough of them to fully Ascend a character in one day. If your world has run out of them, I recommend entering a friend’s world through co-op mode and asking them if you can farm in their world.
The image above shows the location of all the additional detection blocks that you can find in Fontaine. They are mainly concentrated in the northern part of the region.
The image above shows the locations of all the sub-detection modules you use. can be found in the Fontaine dungeons. They are located directly below the areas shown above ground in the previous image, so you can access them by swimming or entering the cave.