- Anything that interacts with adjacent lands, including Push and Gather (since there are no adjacent lands);
- Invader Actions;
- Anything conditional on having a particular terrain or being Coastal;
- Anything that references the board that target land is on.
Effects that do resolve, but generally not in a useful way:
- Defend and other Damage penalties to Invaders;
- Isolate;
- Skipping Invader Actions.
All other standard effects (Fear, Damage, Destroy, Remove, Replace, Add, Upgrade, Downgrade) work as they normally would, albeit with the exception that adding Blight doesn't destroy Presence or cascade, since the Endless Dark isn't a land. (Thematically, there isn't a real ecosystem to damage.)