Area of Effect

It is more complex to understand the true DPS of an AOE weapon. On DPS charts they seem underpowered, for the per unit hit is low. This makes comparison more difficult, but not impossible. Consider the below to better understand the mechanics that make up its DPS and how you can micro your squads to better deal and mitigate AOE damage.

Types of Area of Effect
Some weapons, abilities or special attacks are area of effect (AOE). There are two basic kinds of AOE:
 * Circle
 * Pie.

Flamers are an example of a pie AOE weapon. Awakened deceiver blasts are an example of a circle AOE.

For abilities, there is also burst AOE (which takes effect immediately) and damage over time (DoT) AOE. Weapons and special attacks always take effect immediately.

Frag grenade is an example of burst AOE. Chaos Sorcerer's Corruption is an example of DoT AOE.

The importance of AOE
The greater the radius, the more models hit. This means:
 * More total DPS dealt
 * More morale damage dealt

In the case of DoT AOE, the longer you stay in the radius, the more hits taken.

Micro of AOE weapons is often about maximising the number of models hit. This is of increased importance for units such as the Necron Deceiver, whose dominance of the battlefield depends on this concern.

This is affected by the following

 * Radius of the weapon, ability or special attack
 * How closely packed the models in the target squad maintain themselves, in other words the formation. There are four general kinds of formations that a unit can be in:
 * The standard formation (this is the formation that a squad will try to maintain)
 * The line formation (this is the formation that a squad will fall into, when it must fire at the maximum permissible range. This formation primarily happens with larger squads, where the rear models of the squad are out of range of the enemy despite the front models of the squad being in range)
 * Melee formation (units in melee try to engage in 1v1s, which leads to a spread more similar to the standard formation. The faction that outnumbers the other in melee will surround the enemy, and therefore cluster more tightly - leading to a greater suspectibility to AOE)
 * Disrupted formation (this is the formation the unit is in after being disrupted by a weapon that can displace others with force, such as a fully researched Deceiver. Ironically, this spreads out the squad which means less damage received from AOE. Therefore, in certain cases it is inadvisable to keep attacking the same unit with AOE.)
 * Momentary variations in how closely packed units are. Such movement distortions are affected by:
 * Collisions with other units, as they move around each other
 * Terrain
 * Momentary differences in movement speed, for example due to partially crossing terrain
 * Disruption (such as from a Basilisk)
 * In certain cases the angle that you attack the enemy may matter.

From playtesting, we found the following number of models hit with each attack (based on the radius):

Formations
In order to move back into the standard formation, simply issue a movement command.

Squads of the same faction may have a different formation. For example, AOE attacks have a tendency to hit more shootas than sluggas.

Having a larger formation is not always an advantage, though it does mean you're less susceptible to AOE. It means:
 * The squad is more unwieldy to use. This matters when navigating large terrain pieces. This is unlike Tabletop 40k where you control individual models, as you control squads of models with their own behaviour.
 * It means the squad has to move more in order to get fully into combat range, which is a kind of inefficiency.

Having said this, models in a larger formation find it easier to tie up multiple enemy squads in melee.

Balancing
Area of Effect manufactures an extra dimension to balancing. Units, such as the whirlwind, may be more or less effective depending on how many models get hit per shot. Fortunately:
 * Since AOE attacks tend to also deal disruption (forcing set up weapons such as Heavy Bolters to re-deploy) and Orks and IG squads lack set up weapons, Orks are less impacted from that point of view.
 * Orks and IG have their own ways to mitigate some of the vastly increased morale damage they would take.

Artillery
As a side note to think about, artillery units (which are AOE) tend to have a 60-70% chance of hitting the intended target directly, and the rest of the chance to displace in a random direction. This means that:
 * The benefit of artillery increases as you have more units, as there is a greater chance of hitting a unit.
 * The DPS of artillery increases throughout the game, as squads get larger and the necessity to cluster to concentrate force increases.

Ground Attack with AOE
You have two choices when shooting at a unit:
 * Target normally, as you would do for non-AOE.
 * Ground attack.

Ground attack increases your damage output
Attacking normally can be terribly inefficient.

For example:
 * The Leman Russ Demolisher's cannon is anti-structure AOE.
 * If you normal attack at an LP2, then only that LP2 (and adjacent builders or units) will be hit.
 * If you ground attack to the side of the LP2, then you can even hit a turret that is adjacent to the LP2. In essence, you've doubled its total damage.

Ground attack means you disrupt more models
It is common for a unit with displacement force in its AOE to mis-target such that it shoots only one or two models that have been separated from the target squad's formation.

Ground attack the area of the squad that has: Targeting normally may mean units (such as with grenade launchers) incorrectly target models without special weapons, which can be a disaster.
 * The highest concentration of troops
 * The special weapons you wish to disrupt (such as grenade launchers against Heavy Bolters)