iPhone 6s Plus experiencing unexpected touch input Recently, my iPhone 6s Plus randomly starts opening programs and games one after the other until I shut it down. Then yesterday when I was on a phone call, numbers started rolling across the top of the screen like it was trying to dial. Today, when I was on a call, it disconnected twice with the message "system failure!"

Any idea what is going on?  It is a little over a year old.
It is recommended to get your iPhone inspected by an Apple authorised technician. It appears there is something wrong with the hardware. It is also advisable to update to the latest version of iOS (iOS 11.3 as of this writing). You can try resetting your device (after taking a backup), and see if that resolves the problem.