Thanks! I find the existing answers + examples of a rogue using reaction+sneak attack across multiple ally turns in one combat round hard to follow. Existing examples assume the rogue isn’t low level. A gridded example as in 3.0 would be great. Rogues can Sneak Attack once per turn (individual creature's turn, not per round).

So a 1st-level rogue can attack a target and Sneak Attack on the rogue's turn. If that creature moves away later during its turn, the rogue can make an Opportunity Attack and possibly SA again.

— Dan Dillon 👥 (@Dan_Dillon_1) January 19, 2020