Batman can kick an implausible amount of ass, but he still doesn't mind some help when the thugs-to-batfists ratio gets a little too lopsided. This latest video from Rocksteady thoroughly explains how Dual Play nestles into the Arkham series' beloved FreeFlow combat.
It starts off with the World's Greatest Detective finding one of the Penguin's weapon caches. Apparently no one thought to set up the cache in a building without a glass roof. Anyway, once Batman comes crashing down, he's joined in battle by the stun-rod wielding Nightwing. Thug-tossing combo attacks ensue.
The best part is that your combo count and special meter persist between Batman and his buddy; if your dynamic duo is spread out well enough, you never need to worry about dropping a big combo just because the last few thugs are too far away to clobber in time.
You'll notice that fights tend to be a bit bigger, too - Rocksteady sprinkled more dehydrated thug flakes into Batman: Arkham Knight to account for the fact that four fists crack skulls faster than two. Given how influential Arkham's combat has been for action games in the last six years, I wouldn't be surprised to see this kind of mid-brawl team-up spread beyond Gotham very soon.