Adventurers!
A new article from Baron Jeremy Crawford clarify rules about:
- Sneak Attack once per round
- Attack ability modifier
- Breath weapon
- Magic weapons
http://dnd.wizards.com/articles/features/rules-answers-february-2016
You can download Sage Advice compendium Version 1.07 here:
http://media.wizards.com/2015/downloads/dnd/SA_Compendium.pdf