The vast majority of pug matches are decided by simply how much damage is dealt to another team. This guide is for those who want to become damage-dealing gods and be useful to the team in the best imaginable way: annihilating all opposition on the battlefield. If you prefer using weapons you like and are not so much about minmaxing your performance, you may disregard this guide.
Examples:







Builds used are:
Cicada 3M
340XL
3xML+Tag
14DHS
Atlas D-DC
300STD
2xLL, 2xSRM6, Gauss
19DHS
Heat:
The build of your mech is essential to dealing silly amounts of damage. The primary issue, especially with higher tonnage mechs, is heat. Every weapon choice you make should be assessed with heat efficiency, rather than pure damage, in mind. Many players like to shove their big mechs full of weapons, but can only fire a few salvos before having to tone down the damage and wait for their mech to cool down. This makes their initial DPS somewhat higher, but their DPS throughout the match ends up much lower. Sustainability over burst damage is the way to go.
Heatsinks are often the better choice for your critical slots than another weapon, or a weapon that does more damage but takes more crit slots. For example, I could build my Atlas AS7-D-DC with 2xLL, 3xSRM6 and an AC20. It would probably be the highest initial damage brawler build available and I ran it for a good while myself. However, I consistently do worse damage with that build, even at short range, compared to 2xLL, 2xSRM6 and a gauss simply because I can't fire constantly with all the weapons at my disposal. The latter allows me to do that for much longer periods with the extra heat sinks I can fit into it, as well as the gauss being much more efficient than the AC20, and the damage output over matches is significantly increased.
Weapon choices:
Always try to go for large lasers in energy slots. They're more heat efficient than medium lasers. If you're sporting a faster mech with loads of energy hardpoints, consider going all small lasers for maximum heat efficiency. Medium lasers are the worst choice and should only be used if there's no tonnage to fit large lasers and not enough hardpoints to boat small lasers. Try not to mix laser types, it makes efficient usage with other weapons difficult. More on that later.
ER lasers, pulse lasers and PPC's are very inefficient and should never be used, ever.
For missile slots, it's always better for heat efficiency to use fewer of the larger variants, like LRM20 and SRM6, than more of the smaller variants. You might have more initial missile DPS by boating LRM10 or SRM4 but the heat efficiency suffers and you probably can't sustain laser fire while shooting missiles.
Always go for a gauss in your ballistic slots if possible, autocannons are hugely inefficient in comparison.
In short, you should build your mech towards being able to fire all your weapons, all the time, without overheating.
Always take the shot:
I constantly see people playing the game not taking shots they could be taking. Maybe the enemy is out of optimal weapon range, maybe they figure they can't hit, maybe they don't want to waste ammo or heat on uncertain shots, or maybe they figure it's best to focus on maneuvering and avoiding damage. This is all wrong.
Always take the shot. If it's a moving target way out of optimal range, if you can potentially do any damage at all with the shot, take it. Always try to keep all your weapons on cooldown if you possibly can. This all translates to damage done and better performance. A heat-efficient build is essential to this. Also, bring enough ammo to be able to afford uncertain shots.
Never run ( unless light ):
If you end up getting zerged, don't bother trying to run on anything slower than a scout mech. Instead, use all the time you have to dump as much damage on the enemy as possible before you die. It's better for your team. Don't panic, but aggressively pursue any enemy you can get an easy shot at for as long as you live.
Maintain contact:
Any time spent not in contact with an enemy in range is time wasted. This is time when the enemy is able to fire on your allies, while you're not firing on them. Always try to maximize exposure time to keep consistently doing damage. Never choose a long trudge over the map to go capping if you can engage a skirmish going on right next to you. Always go for the closest/easiest targets instead of pursuing targets that would require you to close in and/or reposition and therefore spend time not doing damage.
Use easy weapons:
You should go for weapons and weapon groups that are easy to use with each other. For example, to get the maximum potential from AC2's you have to constantly ensure that you have the correct lead when firing them, which excludes you from firing lasers or SRM's at the same time. This is terribly inefficient. Use weapons that have longer cooldowns but do a lot of damage whenever you fire them.
For example, on my D-DC Atlas build outlined above, I can first fire lasers, then move the crosshair to appropriately lead the target for the gauss, fire that and then move the crosshair again to appropriately lead the target for SRM6's. I can do all this before the lasers recharge again. This way I can keep firing the three groups in succession while having plenty of time to adjust lead for each group without missing a single cooldown. If I had an AC2, or more weapons groups, it would be very hard to keep all weapons at cooldown while leading all of them appropriately and therefore efficiency would suffer.
The damage-dealing staple:
Large lasers are by far the most damaging weapon in the game right now in the long term. Their ease of use, range and relatively small size and decent heat efficiency makes them easily do the most damage out of any of my weapons throughout matches. My staple weapons for any larger than light build are firstly two large lasers. Then I see what else I could possibly fit there. The more large lasers, the merrier. If you can build a mech with four large lasers and a gauss, go for it. The other weapons are there to pad the damage without wrecking heat efficiency and only support the main weapons, which are the lasers. Considering cooldowns, it's always important to get the lasers off first and then focus on the other weapons, firing the lasers again at first chance.
In conclusion:
The TL;DR version is to always maintain contact to enemy, always keep all weapons on CD and build towards being able to fire constantly and accurately with all weapons rather than being able to do a lot of burst damage and then having to wait around for heat to fall off.