I don’t get #dnd jump rules. Why isn’t it just an athletics check?

— SlyFlourish (@SlyFlourish) April 3, 2018

Or you could leap a distance in feet equal to your Strength score. 😉

— Jeremy Crawford (@JeremyECrawford) April 3, 2018

Would you roll an athletics check for jumps that exceed that number?

— Infamous MOB (@TheThirdFlash) April 3, 2018

Ability checks are an open-ended mechanism that a DM can use to determine whether you succeed at things not specified in the rules:

1. Describe what you're trying.
2. The DM decides if an ability check is warranted. If so, the DM chooses the ability, the DC & maybe a skill. #DnD https://t.co/vi0viMvJRT

— Jeremy Crawford (@JeremyECrawford) April 3, 2018

@JeremyECrawford I've got a question: How is it possible that a wizard can scribe spells in their book with no writing or calligraphy proficiency? Scribing more spells requires "rare and magic ink" so why don't wizard get proficiency to write with the ink?

It makes no sense.

— Freelance Spy (@BenMcLean5) April 12, 2018

Calligraphy is a trade/art form. Knowing how to write spells doesn’t make you a calligrapher any more than knowing how to write sheet music does.
A wizard can use calligraphy tools with or without proficiency. So are you saying that the wizard can perfectly scribe the intricate sigils or runes with no skill check, but can't write fancy letters with mundane ink and pen?
Not saying you are wrong but I am suspicious of the legitimacy of the RAW here.

— Freelance Spy (@BenMcLean5) April 12, 2018

Yes, a wizard is adept at doing something that is fundamental to being a wizard: writing the text and symbols of a spellbook, which is the foundation of the wizard's spellcasting.

— Jeremy Crawford (@JeremyECrawford) April 12, 2018

So does that mean that expertise doesn't stack as well? Like, when you multiclass a rogue as a bard, which both get expertise, the bard would't get the extra expertise from the rogue? Or is this one an exception/gets handled differently?

— Ragelock (@Travelyfied) April 13, 2018

The multiclass rules say you get the features of the class you're multiclassing into, so you get them. Enjoy!

Those rules do make some exceptions about the following:

• Channel Divinity
• Extra Attack
• Unarmored Defense
• Spellcasting#DnD https://t.co/s6c3kUDdxV

— Jeremy Crawford (@JeremyECrawford) April 13, 2018