Helldivers 2

For mortar it's actually quite easy to avoid if you are in a pretty messy fight, aka, you are doding the hunters and patrols heading toward your location. Just follow these simple instructions.

• mortar fires in group of 3 rounds when it detects enemies. It slightly predicts and shoots a bit spread out where the enemy was heading.
• when you hear the mortar popping, look up a bit like you would look for bile spewer/automaton mortar, you can quickly know if mortar is heading your way. this is useful for location defending situation and mortar is near by, less applicable if it's sound are masked out if too far away. But if mortar not heading to your location, fine, if it is, start dashing away from where you were.
• You should be able to avoid 1~2 shots just by moving away, and if you see the shots are "chasing you" then you have to turn 90 degree either way and dive and stay prone until 3rd shot landed.
• If you don't have enemies around you then you are safe for the next round, but if you do, kill the one closest to you in the next 5 seconds.

Bonus tip, mortar have close range limit, means if you stay near the mortar you can defend it better + not getting hit. So if the squads bring more than 1 mortar, make sure they are deployed closer. It's still very useful tool even for high level eradication or any mission objective that you need to clear and then defend.(ie. like ICBM generator and the launch pad, SSSD upload), also good for clear base and distract in automaton side so you can go in and wreck then leave.