In "Dunwich Horror", (DH) whenever a monster enters a vortex, a DH token is added to the DH track and the terror level is increased by one. In "Innsmouth Horror", (IH) whenever a monster enters a vortex, a Deep Ones Rising (DOR) token is added to the DOR track and the terror level is increased by one. However, what happens when you're playing with both the DH board and the IH board, and a monster enters a vortex on either board? Do you ignore the DH effect when a monster enters an IH vortex and vice versa, or do the effects add up? The latter seems a bit extreme, as the terror level would then increase by two for each monster which enters a vortex. So a third interpretation could be to increase the terror level by one, as this is an overlapping effect, but add a DH token to the DH track as well as a DOR token to the DOR track. What are you supposed to do in this situation?

The terror level increases if a monster enters any vortex. But depending on if it's in Dunwich or Innsmouth, you'll either add a DH token or a DOR token. Each track is based only on its respective town.

Thanks for the clarification! =)