Princes of the Apocalypse
Languages - Languages are an important part of the culture of the North, and anyone living in the region are more likely to speak several languages. In addition to languages you learn from your background and class, you may pick a number of additional languages equal to your intelligence modifier.
Inspiration - Inspiration has been greatly expanded on.
Perception and Investigation - Perception is for noticing unusual occurrences in your surroundings. Perception will rarely be rolled, and will almost always use passive perception. If a character is actively searching an area, Investigation will be used instead.
Example: The characters enter a room where a trap is located. Finding the trap is a DC 16. The party's passive perceptions are 12, 13, 13, and 15. None of them see the trap and the room is described omitting that information. If one of the players then search for traps, they can roll an Investigation check. If they roll higher than a 16, they discover the trap.
Sleeping in Armor - Sleeping in armor is possible, but over time it catches up to you. Each night you choose to sleep in armor, make a Constitution Saving Throw, based on the armor type. If the saving throw fails, you suffer one level of exhaustion. Each night armor is worn, the save increases by +2.
DC 7 for light armor
DC 10 for medium armor
DC 13 for heavy armor