While speaking with IGN to promote the recent release of Batman: The Killing Joke, Kevin Conroy explained the importance of restraint in playing Batman properly.
In Justice League, there are often episodes where I’ll have four or five lines, where in Batman: The Animated Series I was used to having the entire script to create a portrait of the character.
But it is harder to do because the temptation is push it when you’re sharing the stage with lots of other actors.
When a character becomes part of an ensemble there’s a certain impulse to make the most of the lines you’re given, but Conroy insists that one should avoid such a compulsion.