The Zero Effect is as of yet unexplained phenomenon first introduced in Magical Record Lyrical Nanoha Force. Its properties apparently include high destructive potential to both living beings and inanimate objects, anti-magic effects, and disruption of electronics (including cyborg endoskeletons). Only Eclipse Drivers seem to be able to invoke the Zero Effect, due to their infection with the Eclipse.
The Zero Effect seems to be partly based on the electromagnetic pulse (EMP) technology, which knocks out all electronic devices in a large radius. However, Divide Zero "Eclipse" is additionally able to affect magical devices and living beings.
So far, the Zero Effect has been encountered in two forms:
- Divide Zero, a Bombardment-type spell used by Thoma Avenir in chapter 1.
- Divide Zero "Eclipse", a much more potent Area-of-effect variation, used by Thoma in chapter 9. It is capable of stripping all living beings in the area of magic and rendering most of them unconcious, as well as crippling entire spaceships. Its power affected even Hayate Yagami, who holds the highest canon mage rank of SS, although she was able to recover quickly.