Morale

In addition to Health, units have Morale. When a unit's morale reaches the tipping point it is morale broken. Those squads that are morale broken move slightly slower and deal significantly reduced damage.

As units then move slower, they are easier to kite and chase. You can think of morale damage weapons as anti-mobility weapons. As artillery weapon are morale damage weapon and also disruption weapons (that break apart your formation and provide what is effectively crowd control) you could see them as apex anti-mobility weapons.

When you have very few sources of morale damage, such as 1 or 2 flamers, then the enemy morale will only slowly deplete. In this scenario your goal is to apply additional pressure in longer fights and perhaps force the enemy to engage you in cover or in melee.

The fewer units you have, the greater your vulnerability to morale damage because a greater proportion of your army would be undermined when they morale break. A subtle conclusion of this fact means that buying special weapons actually makes you more vulnerable to morale damage weapons, as you could have bought more squads or the means to mitigate morale damage instead.

However, special weapons when effectively employed reduces the duration of fights as the overall damage output is higher. As a result, gradual morale damage (such as from flamers) actually reduce in value and large sources of morale damage become more important as you try to morale break the enemy before your army is devastated. Being that early game morale damage weapons tend to have below average range, it means you can be ripped apart at a distance from say Heavy Bolters or Plasmaguns. Hence, using morale damage weapons such a flamers later on means that you need some way to close the gap without suffering too painful losses.

Sniper-type weapons (such as Eldar Rangers) deal single target morale damage, which on face value may seem inferior to Area of Effect morale damage. However, as they kill infantry rapidly the target squad also suffer further morale damage loss because when squad members or squad leaders die the squad takes additional morale damage. Hence looking at DPS charts does not give you a clear cut perspective on the efficacy of morale damage weapons.

Area of Effect Weapons
Area of Effect weapons such as Flamers or artillery can hit multiple units with each attack, their morale damage is multiplied that many times over since each squad member's damage contributes to the whole squad's morale damage taken.

Therefore, Morale DPS per Model Hit is a function of the flat morale damage per hit, reload rate and area of effect.

Multiple flamers firing in concert are drastically more effective than artillery at breaking morale, however they're incredibly short range. There is also an opportunity cost there, as the squad has other weapon choices.

Morale loss per model dead
When a squad member dies, the squad takes a flat amount of morale damage. Several squad members dying in quick succession will greatly speed up the process of breaking the squad.

Squad Leader death
The morale loss when a squad leader dies is greater than if the rank-and-file soldier of a squad dies.

As Squad Leaders (when alive) also increase the morale maximum of the squad, the loss of morale can be pretty drastic.

Commander death penalty
Upon death, the army mourns the loss of all commanders (which includes secondary commanders such as the Harlequin).

All units (which includes other commanders) suffer the following for 20 seconds:
 * Morale maximum squad modifier - reduced by 33%

All vehicles suffer the following for 20 seconds: As Commanders (when alive) also increase the morale maximum of the squad, the loss of morale can be pretty drastic.
 * Morale rate squad modifier - reduced by 33%.
 * Reload time weapon modifier - reduced by 25%.

Resisting morale damage
Squads in melee are further protected against ranged firepower and morale damage in the following ways:
 * Decreases the received ranged damage by 32.6%.
 * Decreases the received ranged morale damage by 85%.

Maximum Morale
Certain units - in particular melee units - often are more resistant to morale damage. In certain cases ranged units are too, and they're especially effective at resisting morale damage because it is harder to inflict morale damage upon them.

Importantly, this table does not take into account the ways to increase morale, for example through researches, auras and squad leaders.

Morale increases from squad leaders & commanders
Most squads can have a squad leader, which increases the maximum morale of the squad. This stacks with the moral increase from commanders being attached to a squad.

For example, a Tactical Space Marine squad has 300 maximum morale. With a sergeant that increases to 375. On top of this, with the Force Commander it reaches a lofty 575; Almost a 100% increase!

A Tactical Space Marine's morale recovers at the rate of 10 per second. With a sergeant this increases to 11 (a 10% increase). With a Force Commander on top this, it increases to 12.25 (total of 22.5% increase). Commanders increase morale rate by 1.25, whereas Squad Leaders improve it by 1.

Tau Firewarriors are unique in that you can have two squad leaders. You have two choices: a shield drone and a shasui fire warrior. You can take two shasui fire warriors, to maximally protect yourself from morale damage.

Morale Broken!
Morale tends to break at 150 morale, regardless of the morale maximum.
 * Imperial Guard breaks at between (50-100). The IG have low morale maximums, so break easily.
 * Necrons break at 50 morale. Necrons can teleport once morale broken; so this is a strength or weakness depending on whether you want to teleport or not.

Once broken, it is broken for a minimum amount of time regardless of morale regeneration that varies with each race. Certain units of each race are particularly vulnerable or resistant to morale, as stated in the Exceptions column below.

Abilities that instantly recover morale, such as the Chaos Icon Bearer's Rally, ignore the Minimum Morale Broken Time. This rewards fast reactions.

Daemon Health Degeneration
Daemons suffer health degeneration when their morale breaks, by an amount per second that varies for each daemon.

General

 * Squad leaders increase the maximum morale of the squad.
 * They also tend to be good in melee, which can be used to mitigate morale damage.
 * The commander researches increase the maximum morale of the commander by 50 (and any squad they attach to).

Space Marines

 * Rhino smokescreen reduces morale damage taken by 30%. Additionally, you can embark troops to help them escape.
 * Force Commander's Battle Cry increases the morale maximum by 200, a massive increase.
 * Catechism of the Righteous Emperor improves morale recovery.
 * Space Marine Sargeant's Rally instantly recovers the squad's morale, but afterwards reduces maximum morale by 200 for 20 seconds.

Chaos

 * Icon Bearer instantly recovers morale, but makes the squad vulnerable to further morale damage afterwards.
 * Rhino smokescreen reduces morale damage taken taken by 30%. Additionally, you can embark troops to help them escape.
 * Chaos Lord and Daemon Prince's Daemonic Strength increases morale recovery.
 * Aspiring Champion Berzerker's Blood Frenzy reduces morale ranged damage received by 50%.
 * Aspiring Champion's Furious Rage reduces morale ranged damage received by 50%.
 * Blood Frenzy of Khorne (which provides the Blood Frenzy ability) also increases morale recovery by 30%.
 * Daemonic Presence increases the morale of Possessed Space Marines and Horrors.

Eldar

 * Chosen of Jain Zar research increases banshee morale and reduces the morale ranged damage that they receive.

Tau

 * Tau instead rely on Shield Drones, which provide Firewarriors personal shields to reduce morale damage.
 * Devilfish allows you to embark troops to help them escape.

Imperial Guard

 * As the Command Squad cannot attach, the commander research (with respect to mitigating morale damage) is more about increasing the size of the command squad in order to disrupt anti-morale weapons (like Flamers).
 * Commissar Execute instantly recovers morale and increases the moral maximum of the squad.
 * Morale broken guardsmen can bunker up in structures or man chimera lasguns, without being negatively impacted by morale. While so bunkered, the morale of the guardsmen squad still recovers over time.
 * Priest's Righteous Fury reduces morale damage received by 10%.

Dark Eldar

 * Daughter's of Pain increases morale maximum of Wyches.
 * Mandrake Shadow Skin reduces ranged morale damage by 30%.

Necrons

 * Necron warrior researches (Disruption Field and Enhanced Disruption Field) each increase the maximum morale of the squad by 50.