LRMs (MechWarrior Online)

LRMs (Long Range Missiles) are a weapon system divided into 4 sizes per faction (8 variants per faction if including the additional, non-mixable Artemis IV variants), part of the MechWarrior Online game. This page includes not only information on the LRMs ingame themselves but also guides about how to build and use them.

History and mechanics
Long Range Missiles have had a long and tortuous history since MWO debuted in 2012.

Originally usable enough, LRMs were nerfed a number of times because players raged on the forums that they were "anti-fun".

LRMs were never competitive play material, since they always dealt spread damage in uncontrollable enemy locations, and there was a number of possible defenses against them, from ECM to Anti-Missile Systems.

However, still many complained that LRM users, or "lurmers" as they were mostly derisively called, would hide in the back lines and wait for an allied target lock to fire. This basically called LRM players "moochers" (to use Ayn Rand terminology) and mobilized organized real-world hatred against them continued through time, arguably utilizing similar sentiments as those in the USA against social security, medicaid and food stamps. Lurmers were also called "noobs" and "bad players" that needed the passive lockon to hit (even being direct fire, short range, and attacking random sections, they were considered "talentless" for locking in quickly).

The repeated calls had effect and LRMs were nerfed a number of times. LRM lockon time was increased, as well as their spread (already the highest of any weapon), making them more inaccurate. LRMs were also hit pretty hard by Ghost Heat (MechWarrior Online), since chanin-firing them isn't conducent to negating protection from AMS. The reticle range in which a lockon is achieved was also diminished to a minuscule percent, making aiming LRMs a serious hurdle (considering even a moment outside of the reticle will reset the lockon time, and enemies move... and lag). Also hit by similar nerfs were Streak SRMs (MechWarrior Online), another non-competitive, lockon weapon.

However, the biggest offender mechanic that forced "lurming" as the only LRM use was left untouched: The mechanic that AMS destroys missiles by health and not by proportion as in the Tabletop Battletech game. This encourages that if you use LRMs, you need to "Boat" them, that is to say, use a large number of LRM weapons together. If you use just a few LRMs, they will all be shot down by the AMS (which combines in team clumps, since it doesn't care whether the missiles are attacking that 'mech specifically); thus, the more LRMs in total you use, the more LRMs in proportion that can go through the AMS "iron dome".

The last major "Overhaul" of LRMs made them behave differently when direct-fired and when indirect-fired, altering their arc. It also firther nerfed indirect fire LRMs. This was done in the hopes that this would encourage direct-firing them. The hopes were misplaced.

Artemis
The Artemis system reduces the spread of LRMs, allowing more to hit the target in general and the torso in particular. It also allows to target faster when doing direct fire, though this bonus isn't cumulative with the NARC beacon.

Artemis are somewhat a pain asministratively as changing your mech from Artemis to Non-Artemis costs C-Bills and the mode isn't "Unlocked", thus you have to pay every time. All LRM and SRM (non-streak) launchers are added or removed a ton and a crit space by this. The ammo is also replaced, but it is functionally identical.

Faction differences
IS launchers are significantly heavier and occupy more critical slots. However, they have lower spread and fire all their missiles instantly, as oppossed to Clan launchers "spreading" the missiles. This makes IS launchers better against AMS in a per-missile basis as well as somewhat more ammo efficient (the ammo itself is identical in both cases, offsetting some of the Clan weight and crit advantage in requiring more ammo in average). However, Clan LRMs do have an advantage - instead of dealing 0 damage as long as the enemy is within 180 meters of the launcher, Clan missiles "taper off" their damage inside that range, so an enemy in 90 meters distance should still receive about 50% damage (in theory-actual values seem to be lower).

While all IS launchers thus fire at the same time (at least in the first salvo, since they also have different cooldowns), the "stream" fire of Clan launchers compounds into their recharge time, thus for example LRM-5s will recharge faster (though still slower than their nominal recycle time) compared to LRM-10s, and if you keep the fire button pressed, their firing will diverge more with each volley (before converging again at different volley counts). While this may be useful as a shortcut to more rapidly avoid ghost heat, it also makes the DPS lower than the nominal value, with the difference increasing in size of the launcher.

Size differences
LRMs, as usual, are divided in 5, 10, 15 and 20 tubes. Like their tabletop game counterparts (and unlike the ones in NimoStar's lostech mod, they become less tonnage efficient as size goes up, with an LRM-20 being way heavier than just using 4 LRM-5. However, there are several mechanics that effectively force you to use the larger launchers. First of them, lowest and most simple is heat efficiency. Larger launchers generate less heat than smaller ones per missile (and thus per damage), and as such require less heatsinks for continued fire. But the more heavy-handed restrictions are Ghost Heat; you can fire just 3 LRM-5 without incurring on Ghost Heat (which, mind you, can easily become lethal and at the very least it ruins your DPS chances), while the limit is 2 LRM-20 = 40 tubes on big launchers vs 15 on small (you can also add an LRM-5 or 10 to the LRM-20s). The other relevant limitation is missile hardpoints: 'Mechs have a limited number of missile-launching points and these have, on their part, limited numbers of maximum missile-launching tubes. Exceeding this tubes means less efficiency while firing = less DPS and AMS avoidance. Exceeding hardpoints is impossible and limits lurming to specific 'Mechs and variants. Missile hardpoints on IS mechs are specially scarce, with few 'Mechs having 4 and even less having more; though those 'mechs that do have hardpoints, tend to have good special Quirks (MechWarrior Online) to make them worth it.

Building a lurmer: Strategy
(in construction)

There is something very important about lurming that people don't usually get: Force multipliers. Playing a missile lock boat correctly has many added "taxes", such as carrying BAP and TAG; but this isn't all, you also need to invest in Sensor quirks (including heavily into sensor deprivation to avoid counter-lurming, and seismic sensors to avoid nerby hidden 'Mechs).

Ammo efficiency and range weapon quirks are fundamental; mobility quirks are favored to get into position and not stray too much. Missile critical damage quirks are meh: Crits are extremely rare, only count when damaging structure and not armor, and no missile type has bonus chance of getting them. Missile speed is even more important than range, since it determines how likely it is to hit by denying cover opportunities (remember enemies are warned of missiles beforehand). In any case, your 'Mech may be better off NOT lurming until it has at least tha basic sensor skills, not to mention TAG and BAP.

Lurm mechs often benefit from XL engines; endosteel may also be taken, but Ferro-Fibrous armor is usually not favored, since it eats too many spaces (Remember: never take Ferro-Fibrous without using Endosteel first, specially as IS, since Endosteel saves way more tonnage per crit). As such, Missile Boats aren't C-bill cheap. In fact, you are highly advised to take UAV with you, if your damage can offset the costs. This is specially true if you have premium time enabled. The UAV gives you (and your team) extra vision and lockons, which are extremely important. Artillery strikes and Aistrikes may also force enemies to move away from their cover, thus getting in the position to be showered by your LRMs (and your teammate's fire as well).

Now that we have gotten the auxiliary part out of the way, what's the best way of actually building your lurms? Other than bringing BAP and TAG, remember TAG and Artemis stack with eachother, but not with NARC. So if you use NARC, its probably best to skip TAG and Artemis. NARC however has very little ammo and is tricky to use, because its maximum range is 600 meters, it doesn't lock on, and it's direct fire only. Not only that but it consumes one of your missile hardpoints (meaning you would need at least three hardpoints in total to be worth it). If you can master it and it works, good for you, otherwise sticking to TAG and Artemis is the more efficient idea.

However, there is a catch with Artemis in LRMs: The smaller the launcher, the less efficient the Artemis system. An Artemis addon always costs 1 ton and 1 crit, be it on an LRM-5 or an LRM-20... so, never use it on LRM-5, and try to get it just on LRM-15 and LRM-20 if possible. These launchers also need them more, because they have larger spreads, so without Artemis, they have a greater tendency to miss or to deal damage to arms and legs. Still, Artemis on LRM-15 is not completely mandatory and on Medium or specially lighter 'mechs you may need the tonnage direly for auxiliary weapons or more ammo. In any case, Light 'mechs are better off using their hardpoints in lots of LRM-5 (six LRM-5 in two groups of three to avoid ghost heat is a good mini-lurm Clan light boat, achievable on select chassis/omnipod configurations).

As for the auxiliary weapons, youhave got more options than it seems - Though you should avoid things like Rocket Launchers, since they also have minimum range and limited life, thus sharing weaknesses with the LRMs.

Auxiliary Weapons
The lurm "blind spot" means you are basically obligated to take something else if you want to be a functional human being fully prepared 'mech for all circumstances. Here are some auxiliary weapons options, ranked from best to worst:
 * Lasers: Normally they are given as an universal - lasers in MWO are just OP (which also makes them meh if you are about that sort of thing). Either you run them as your main/sole weapons or as your support - there is normally no escape. As an LRM boat, lasers are useful for finishing off damaged armor and components, as well as for complimentary damage and low-range defense. Remember however that targeting computers don't help any missiles at all so they are discouraged. Medium ER and, if Clan, Heavy lasers may be preferred, since they are most tonnage efficient, and when you fire them alone (as within the 180 m range or without a lockon), most of your heat will be free. They don't require ammo and even extra heatsinks are optional (and would help your sustained lurming anyways). However, perhaps the key to understanding why lasers are so good with lurms hinges on their firing modality: Your reticle must be set exactly on the enemy mech for instant damage over a period of time, which synergizes very well with getting that sweet lockon. Hey, you know what they say: Hate the game, not the playa´
 * SRMs: Take into account these share your Artemis, so if using Artemis, you should get SRM-6 to maximize the efficiency. The good part of these launchers is that they share your missile quirks, they help to nullify AMS as well, and they cover your short range pretty well, as well as being almost as light as Lasers. The bad part is they require ammo and your missile slots. No ammo = Sitting duck and inglorious death. Also, SRMs may also need to anticipate enemy movement - in some circumstances this will make your LRM lockon fail, though their range overlap is fairly small anyways (merely 90 in 180-270). However, if the enemy is staring at you in that range, fire everything and watch him burn.
 * Streak SRMs: Streak SRMs will help your lockon time when within their range (360 m, normally), helping to get that medium-range direct fire targets. They still don't share ghost heat, and can also help counter enemy AMS with additional, hardy and fast missiles. However, Streak SRMs can't fire without a lockon and you should ALWAYS bring them with a BAP and TAG. Their targeting of parts is erratic so they are more damage farmers than enemy killers, unless your enemies are 'light mechs. Even then, Streak SRMs will lose their lock point blank thus can't fire there, a weakness experienced enemy pilots are likely to exploit. Perhaps a single small streak and lasers is the best use of this weapon, almost exclusively to aid your lockon.
 * ATMs: This is more of a complement to your Clan LRMs than an auxiliary weapon, since you also should have something else; but a lifehack is to not use Artemis and use an ATM-3 instead. Since ATMs come with incorporated artemis, this helps your lockon time as if you had it (but not LRM spread or tracking). The ATM also packs a punch similar to the SRM, though it also has a blind spot on 120 range. ATM boats are their own archetype discussed on ATM (Mechwarrior Online). They share ghost heat and thus have to be managed as if an extra LRM.
 * PPCs: While PPCs disable ECM for like 4.5 seconds on a direct hit, it is very hard to make this difference count. The non-instant nature of PPC fire also means that you are probably sacrificing missile lockon unless the enemy is static or coming right at you. PPCs are also quite heavy and you need that tonnage. Not extremely bad but also not good. On the plus side, they do deal a good amount of instant damage without requiring ammo and aren't quite crit intensive. ER PPCs and Snub Nose PPCs are the viable ones, since regular/heavy/light PPCs have a blind area that along with the LRMs would be your undoing.
 * Machineguns: While fine in theory, it is very rare that you could get enough machineguns to make a difference, due to the limitations of combining missiles and ballistic hardpoints (very few 'mechs or omnipod configurations can manage enough of both to make a difference - again, hate the game and its laser infatuation). As extras they are fine. Take into account that while MGs use a spray bullet animation, they are actually instahit weapons much like Flamers, so keeping the opponent on crosshair is best - however, their range will have basically no overlap with LRMs - except partially as Clan Light Machineguns, but then you are sacrificing an already meager DPS.
 * Autocannons: Seriously? Non-machinegun ballistics are heavy, direct fire, no lockon, and intensely ammo dependent weapons. You are better off with missiles and lasers, or ballistics and lasers. Missiles and UAC/20 may sound fine in theory, but the weight and slots you sacrifice are too much, and two SRM-6 or four Medium Lasers would deal as much damage with a much lighter footprint. RACs could be possible, specially RAC/2 as you don't need to lead the enemy movements too much and can keep them under your crosshairs a lot - but they are still heavy and managing the spin up and jams would make the configuration extremely unwieldy. Basically, in this case you need to really hate the game. And possibly yourself.
 * Gauss Rifles: You madman. Gauss are heavy, big, need to charge, need to anticipate enemy's movement (so no lockon stare as with lasers or Streak SRMs), use ammo... They also explode (do NOT store LRM ammo in the same section, and always use CASE). This is a terrible idea, so don't say I didn't warn you.

Being a lurmer: Tactics
Forget about building anything not-lurming from LRMs: If you use LRMs, you need to go all in, for reasons explained above. Otherwise your missiles will be rendered useless by enemy AMS.

Somewhat counterintuitively, survivavility is key to building an LRM boat. As Sun Tzu (the actual Chinese philosopher-general, not Sun-Tzu Liao) would say, the most important part of any battle or war is simply to outlive your enemy. In Skirmish games this is particularly important but it will come into play in any mode... particularly as we have to focus mobility, not armor.

Staying out of the "push" front line is the key part to making your LRM hateboat shine, no matter how much hate. If the enemy closes into melee distance and you have no support, your auxiliary weapons will not save you, even as a clanner with "technically no minimum range". The opponents will use any chance to get to you and shoot you point blank, where your LRMs can neither lockon or deal damage. Your support weapons and your teammates are invaluable at these times, but more so is the ability to ensure that doesn't happen.

Mobility will make sure your heavy or assault lurmboat doesn't stay too far behind your group, and catch up with them. Even if you are at the rear, you should always have teammates in sight in these cases. With light and medium 'mechs, this is somewhat less necessary, but ATMs and SRMs befit a lone wolf more than LRMs anyways.

In the later stages of the game is where the enemies will be disperse and damaged enough that you can get the last laught from your lurms. Hunt crippled and damaged 'mechs with the combined power of LRMs and support weapons. As the enemies scatter, their ECM and AMS will be less effective, and you will be able to counter them more easily with your own BAP, TAG, etc. Non-laser AMS also run out of ammo, not to mention the ones that are destroyed on the course of the fight.

This doesn't mean you wait and do nothing until the end; your LRMs are a strategic asset as you will be often one of the first to fire. So, bring lots of ammo so you can keep firing until the very end. 40 tubes of LRM (and you should never bring less than 30 at the very least) means 4-5 tons of LRM ammo at the bare minimum. Even then, wait for the feedback (red haircrosses) to let you know if to keep firing, otherwise you are just wasting your precious missile cargo - and you will always need it. There is no such thing as too many LRM missiles. Even the largest missile reserves can be depleted in drawn-out games, and red crosshairs could mean just a single missile of your 30 hits (the amount of missiles is more noticeable to estimate roughly with 'clan streamfire, whereas with IS they will be practically hit simultaneus).

It is almost certain you will be out of missiles in a long game sooner or later, but if you have lasers or even a PPC (with unlimited shots), that will be the time to bring them to bear in full. Even relatively light energy weapons such as 3/4 medium lasers can make a very big difference and be a formidable force when used against damaged opponents in the late game (you should identify and attack vulnerable, armorless enemy sections). Thus is the key to victory.

As for the range of Lurming, 500-600 approximately is a good range to lurm. 900m and similar (even if you extend to 100m with quirks) tends to waste ammo since enemies have WAY too much time to have cover. Also take into account that if you lose lock, your LRMs are very likely to fail - and this gets increasingly likely as range advances. In fact, enemies within 300-400 meters are the most vulnerable, but such occassions are rare and let them get into your no-go zone; however, if it does happen, shower them with everything you got (including auxiliary weapons and call allies) to finish them or cripple them enough before they get to you. Covering alone from a single determined advancing enemy will do little, since all they have to do is to close the distance.

Remember always that you can also always fire LRMs without a lockon (though they will still deal 0 damage if IS within 180 m). This is known and "dumb firing" and works the same as any other weapon - with the exception os Streak SRMs, which can't fire without a lockon at all.

Some extra advice: Keeping your TAG on gives off zero heat, costs zero ammo, and helps you counter ECM and target sooner. You should have a weapon group that is just your TAG (that there is no key to just keep the TAG on without having to perma-click is a game FAIL). The only disadvantage is has is that it can give off your position, but since you are direct-firing by this point, it shoudn't be much to worry about.

If you deal enough damage and get sufficient assists/kills, maybe your teammates will not curse your name for bringing a lurm into a laserfight. Maybe being the operative word.

Universal MWO LRM stats
All LRMs have a nominal speed of 210 when indirect fired, and hold 240 (shareable) ammo per ton in any configuration. While listed in table, all LRMs have a default max range of 900 (extensible by skill tree up to a max of about 1030 with Weapon Range modules).

LRM Stats
Additional shared stats: All IS LRMs have a 0.3 Impulse rating. All Clan LRMs have a 0.15 Impulse rating.