Railguns and the return of selective warship armor

Could railguns lead to neo-dreadnoughts, and how would modern ships protect themselves from hypervelocity fire?

Railguns might favor large-gun cruisers, while armor would likely return around vital spaces and as energy-reducing layers rather than as a full battleship belt intended to stop every shot.

A return of the large-gun cruiser looks more plausible than a literal dreadnought. Hypervelocity weapons would extend line-of-sight and beyond-horizon fire, but armor would be selective: protection around magazines, engineering spaces, and the combat information center, plus plates intended to strip energy or control damage rather than stop every penetrator. Armor can still be useful even when it cannot make a ship invulnerable.