Let’s say I have UI on the bottom border of my game.
Now, I want to add Admob and do banner ads.
What happens to the UI, is it just moved up? Does the ad change the screen resolution, or does it go “over” my UI?
Mobile game in portrait mode.
Thanks for any insight you might give!
Hi and welcome here 
I think you are supposed to leave empty space for the banner, but the best way to find out is to try.
Be careful, if buttons are overlapping ads or simply too close, Google may consider that you’re trying to trick users into clicking on the ads, and disable your account.
Thank you so much! That’s really good to know. I’ve built a bar into the bottom of my screen now for ads, and I’m hoping it’s far enough away from the buttons. It’s not a really fast-paced game.
If not I can re-create it at the top, although I’d prefer to keep the top of the screen ad-free
Just in case anyone else find this, I finally set up Admob and packaged my game for Android to test this out. When the banner appears, it moves the rest of the screen up. I had built in a spot on the page for it, but it pushes everything up so I didn’t need to.
Instead, I modified that “blank space” into a “buffer” to give a little bit of space between the buttons and the ads at the bottom.
My game is in Portrait mode, just for clarification. So I wouldn’t be sure about landscape mode games like platformers.
Landscape does this too.