@JeremyECrawford we had an at table debate the other day – if a creature is affected by Slow first and then Haste by an ally/potion, what happens? #dnd do they cancel or do the effects act simultaneously?

— Luke Pickles (@lukempickles) June 26, 2018

Spell A doesn't cancel spell B unless the text of spell A says it does. #DnD https://t.co/AIidnLaNfx

— Jeremy Crawford (@JeremyECrawford) June 26, 2018