Originally Posted by
Anggul
Cover rules are the same for everything. 25%+ of the model covered, from the point of view of the firer, you get cover. Any less than 25%, no cover. The other is area terrain. Two classifications. No more, no less. An Aegis is just a piece of cover that grants a 4+ cover save in the same way as any cover, which is to say it has to cover 25% of the model to provide said save.
If a model is far away from the aegis line but is still covering at least 25% of the model from the firers point of view, it gets cover, you're still trying to shoot over the wall. A Wraithknight or Riptide is never going to get cover behind an Aegis unless the Aegis is raised up on a hill or something, they're just too big otherwise.