This is how Ben Affleck and Geoff Johns are working together on a Batman script

“He’s been working on a solo script with Geoff Johns as well. Last conversation I had with Geoff Johns I was like are you working on it? And he said ‘yeah’. I said what’s it like man, how do you co-write with someone? And he’s going we just break it up, he takes halves and I take halves and then we write, and then we switch material, and then he goes over mine and I go over his.”