Using Royal Road in a dungeon and using it in a raid can be a bit different. In a dungeon, you can basically use it however you'd like because regardless of what you Royal Road, the fight will be over in a few minutes. Basically the cards don't hold as high of value in a dungeon-type setting, nor are they game-changers. In a raid, however, the Royal Road effect can be significant. You may understand what the ability does, but that doesn't mean you know how to use it. Dungeons =/= Raid.