I know a lot of you pros will know these things, but for those who don't or I might have something you haven't considered, here's what I have to give:
1. Know what to watch for. You see a very slow Jagermech with two large gun barrels ONLY or a Catapult without the usual "Micky Mouse ears" of LRM racks, and what appear to be gun barrels protruding from under each side of it's torso, you probably have a troll with 2 AC20s. Forewarned is forearmed.
2. NEVER look directly at them. I would rather lose an arm than have most of my core armor blown off in one shot. Even in a front-heavy Atlas you lose over a third in one hit. Anything else is going to be even WORSE off. We're talking half or more of your game chipped away in one hit. This basically ends your front-line role, taking you out of the fight early. Everyone who sees your damaged CT will then try and rush you for an easy kill, making your day even worse.
3. Shoot between their shots. The AC20 has a very predictable recharge time of 4 seconds. Use and abuse your opponent's cooldown. Torso twist and present an arm. Listen for a shot or a hit on your arm or leg (preferably just the sound of a shot) and then turn and fire everything you have at the enemy in that 4 second window. Then twist back sideways, maybe presenting the opposite side than you did before. Rinse and repeat. These builds have very low armor because of all the weight they carry, and can only stand a few solid hits from your average mech. Better, a lot of them run XL engines. Go for a torso and you can often get a quick kill.
4. While doing the above, it is important to keep moving. You have to lead an AC20 when your target moves laterally. Make them miss. Stutter step. Back up, and move forward again. If they can't get a stationary shot to your front or rear they will often shoot wild, and then you have 4 more seconds to pound on them.
5. Keep your distance. They are useless at long range. Use that to your advantage. Back up so they can't close the distance, but still remember to torso twist.
6. Attack vulnerable points. Sometimes, it isn't best to try and core them. Their arms are much more lightly armored, and they can't twist away to buy time if their cannon arms are what they need to protect. A good torso twister running one of these mechs can kill you while you try and core him by spreading your damage. Don't even let them use this tactic. One good alpha to an arm will immediately make a slow, lightly armored mech with an AC20 out of them. Blow off the other and you have a free kill. And it's funny to watch them run away weaponless. Another good option is the legs. They keep their AC20 ammo in there, and armor them lightly. Ammo explosions are your friend in this situation. Also, they aren't going anywhere fast with a missing leg.
Hope these pointers help someone, and if anyone thinks of something I didn't, please share!
Edited by Mcchuggernaut, 09 December 2013 - 04:24 AM.