Arkham Origins Incident
The Baseball Bat appeared in Concept Art and in the demo of Batman: Arkham Origins.
Arkham City Incident
Before Arkham Knight Incident
Arkham Knight Incident
Thugs, once again, were seen using them, but that time, Batman could too. If one was dropped on ground, Batman could pick it up for increased damage and to bypass some enemy weapons. They broke after using them for some time.
The playable version of Harley Quinn used her custom Baseball Bat during Takedowns and Beatdowns.