Editing Warhammer 40,000/8th Edition Tactics (section)

==Playing the Game==
===Movement 101===
{{Main|Warhammer 40,000/Tactics/Movement 101}}

Topics covered so far:
*How movement works.
*Common rules mistakes.
*Basic advice regarding movement.
*Accurate and predictable measuring.
*Countering enemy movement.

===Psychic Phase (AKA: mind bullet time)===
Link to main article: [[Warhammer_40,000/Tactics/Psychic 101(8E)|Psychic Phase 101]]

New as of 7th, the psychic phase is where you use your vast array of mind powers.

===Combat 101===
While Shooting and Fighting are separated below, they largely share rules, much like how Movement and Charging are in separate phases, but share many rules and concepts. By and large, ''any'' attack you make has 5 values: Attacks (which is rate of fire), Accuracy (typically WS or BS), Strength, AP, and Damage. These values are converted into other values in context (for example, attacks are left alone, but accuracy requires dividing by 6), then those values are multiplied together to determine how many wounds you actually expect to knock off your target. They resolve in this order, in general:

#Determine number of Attacks.
#Roll to hit, based on accuracy.
#Roll to wound, based on strength and toughness.
#Target rolls to save, based on its saving throws.
#*While all rolls are subject to re-rolls and modifiers, the most common modifiers in the game apply here, such as AP and Cover.
#Roll to damage.
#If the target has a "Feel No Pain" type rule, it rolls that against damage, much like a saving throw. Feel No Pain rules cannot stack with each other- only the strongest one is applied. 

As will be discussed below, you ''always'' re-roll ''before'' applying modifiers.

====Attacks====
This can be random, such as 1d3, or 1d6, or 2d3. There is a section below on dice averages, but for attacks, you can safely treat a random value as its average for the purposes of working out how much damage a given attack will do to a given target. More often, it will be a constant number- melee weapons generally use the Attacks stat of the user, while ranged weapons will specify the number of attacks they can perform in their profile.

====Hitting====
By and large, this will be a WS or BS value. Regardless of the name of the stat, here called "AS" for "Accuracy Skill". 

The odds of hitting is: (7-AS-modifier)/6

*An ability to re-roll will multiply this value by (6+x)/6, where x is the number of facings on a hit roll you can re-roll, so if you re-roll 1s x is 1, re-roll 1s, 2s, 3s and 4s x is 4.
*Re-rolling all failed hits means x=7-AS, note that modifiers do not change the effect of re-rolling all failed hits, this is only affected by the AS. 
*Abaddon's ability to re-roll hit rolls even if they hit mean x=7-AS-modifier instead.

====Wounding====
Instead of requiring a fixed roll like hit rolls most wound rolls (WR) instead require that you compare the Strength of the weapon to the target's Toughness, although some weapons do require a fixed roll. 

Your WR is 2+ if S ≥ 2xT, 3+ if S > T, 4+ if S = T, 5+ if S < T, 6+ if 2xS ≤ T

The odds of wounding is: (7-WR-modifier)/6

*An ability to re-roll will multiply this value by (6+x)/6, where x is the number of facings on a wound roll you can re-roll, so if you re-roll 1s x is 1, re-roll 1s, 2s, 3s and 4s x is 4.
*Re-rolling all failed wounds means x=7-AS, note that modifiers do not change the effect of re-rolling all failed wounds, this is only affected by the WR.

====Penetrating Saves====
Basic saving throws work very intuitively, broadly identical to accuracy a 6+ save works just like 6+ to hit - except that the target assigns which model takes the save in the unit and rolls the saving throw, this changes the looks of the math a little since we will be calculating how likely we are to penetrate our opponent's save rather than how likely we are to save. Many weapons have a negative AP value that increases the dice roll your opponent needs to beat to pass their saves, a cover save now adds a +1 modifier to the Sv of the unit rather than providing an alternate save like an invulnerable save like it did in the past. A saving throw roll of 1 is always a failure, but a roll of 6 is not necessarily a success. Invulnerable saves are unaffected by cover and AP but otherwise works exactly the same way as a normal save.

Your odds of penetrating (oop) is (Sv - modifiers - (AP) - 1) / 6 

*Note that oop cannot be greater than 6/6.
*Note that since AP is negative (-1/-2...) the outcome of AP is actually positive -(-1)=+1. 
*An ability to re-roll will multiply this value by (36 * oop - x * (7 + Sv + modifiers + AP) ) / 36 * (oop) where x is the number of facings on a saving throw your opponent can re-roll, so if your opponent re-rolls 1s x is 1, re-roll 1s, 2s, 3s and 4s x is 4.
*Ap increases damage non-linearly, having AP- or AP-1 against a 2+ Sv and a 6+ Sv are very different things, against a 2+ Sv AP- will need 6 wounds to penetrate the save once, while AP-1 will need 3 wounds to penetrate the save once (causing 100% more damage), while against a 6+ Sv AP- will need 1,167 wounds to penetrate the save once, while AP-1 will need 1 wound to penetrate the save once (causing 16,7% more damage).
 
=====Cover=====
Cover improves the Sv of the unit that is in cover by 1 against Shooting attacks regardless of which phase that Shooting attack is made in or whether the target or firing unit is in combat. A model cannot claim multiple cover saves, it is either in cover and receives the bonus or it is not and it does not benefit. If you have a unit that is partially eligible for cover the whole unit will not benefit, but if you remove all the models from the unit that are not eligible the unit benefits immediately, therefore it can be beneficial to roll your saves one at a time and pick off the ones outside cover first. 

*Certain units and terrain types (in the advanced terrain rules) have special rules which require additional restrictions regarding what units count as in cover or not. The best way to negate this if you want to maximize your output is to spread Anti-Armour units out across the board for as many viewpoints as possible. As for actually using this type of cover yourself, your best bet is to park these units inside a building or in a covered corner of the board where the opponent can't try to maneuver into a better place to shoot.
**Most TITANIC units require you to have them '''''in''''' cover '''''and''''' be 50% or more obstructed from view from the shooter (and sometimes this simply doesn't apply to some models). This would found as a special rule of the TITANIC unit itself and is not, strictly speaking, a rule for all TITANIC models. 
**Woods require non-INFANTRY units to be '''''in''''' cover '''''and''''' be 50% or more obstructed from view from the shooter.
**Ruins require non-INFANTRY units to be '''''in''''' cover '''''and''''' be 50% or more obstructed from view from the shooter.
**Craters only provide cover to INFANTRY.
**Barricades require INFANTRY units to be within 1" and behind it from view from the shooter. They do not provide cover to non-infantry.
**Obstacles do not provide cover.
**Imperial Statuary provides cover to MODELS that are within 3" and 25% obscured from the point of view of the firer.
**Fuel Pipes require INFANTRY units to be within 1" and behind it from view from the shooter.  They do not provide cover to non-infantry.
**Battlescapes require non-INFANTRY units to be '''''in''''' cover '''''and''''' be 50% or more obstructed from view from the shooter.
**Hills do not provide cover.
*A special note that terrain obscuring requirements from the view of the shooter doesn't have to be obscured by the terrain feature itself. A Vehicle could be on a Battlescape terrain feature which did not conceal them, but if another terrain feature or model obscured at attacker's view of them, it would meet the requirement to be obscured from the view of the firer.
*Many of the terrain types have additional special rules, but not rules related to meeting the requirements for cover saves.

====Inflicting Damage====
When a model fails its saving throw it takes a number of damage depending on the Damage characteristic of the weapon used. The model suffers that many wounds and any excess wounds are lost. 

Feel No Pain "FNP" style abilities allow models to ignore some of the damage they take on by rolling a dice and beating a number, these rules are exclusive meaning you have to use the best one available but you can use it in addition to your normal saving throw.

Roll a die each time a model with this rule suffers a wound or mortal wound. On a roll of 6, ignore it.
*Sometimes, the roll is a 5.
*A 6+ FNP increases the average number of wounds you need to deal to a model to kill it by 6/5 or 20%. The chance that it will completely nullify an unsaved wound is 1/46656‬ for 6 damage, 1/7776 for 5 damage, 1/1296 for 4 damage, 1/216 for 3 damage, 1/36 for 2 damage and 1/6 for 1 damage. 
*A 5+ FNP increases the average number of wounds you need to deal to a model to kill it by 6/4 or 50%. The chance that it will completely nullify an unsaved wound is 1/729 for 6 damage, 1/243 for 5 damage, 1/81 for 4 damage, 1/27 for 3 damage, 1/9 for 2 damage and 1/3 for 1 damage.

===Shooting 101===
====The basics====
Shooting tactics rule ONE (1): Shoot at something until it is DEAD/destroyed/exploded/gone/fucked/smeared-across-the-floor. Seriously. Anything that is not dead can still hurt you. As the old Tactica Imperialis says: "Concentrate your fire on one target to the exclusion of all else. Once it is gone, choose your next target." Consider heavily before you commit several turns worth of shooting into a big target like a Knight with your lascannons, you might be better off ignoring the Knight and targeting a Leman Russ instead if you cannot kill the Knight in one turn.


Shooting tactics rule TWO (2): Shoot for the mission. At the end of the game each game is won based on Victory Points (VP), don't fall for the distraction carnifex. 


Shooting tactics rule THREE (3): Shoot your weapons with the highest Damage characteristic first, if you deal a wound to a unit of Terminators with your Tactical Squad's bolters leaving one Terminator at one wound and then fire your Overcharged plasma into that squad with Damage two you are wasting 1 damage. If you had shot your plasma first you would get an extra damage for free. The opposite situation exists, if your opponent has a wounded model in a unit it can make sense to try and remove that model with your lower damage weapons in order to get maximum value of your bigger weapons into the next model in the unit. 


Shooting tactics rule FOUR (4): Shoot with the unit with the fewest targets available first. At the start of your shooting phase, assess what target options each one of your shooty units has, and always have your units who only have a single option fire first. The reason for this is if you've got unit A in a position to shoot anything he likes and unit B which only has one thing to shoot at, you want B to take the shot first. If you shoot B's target with A first instead, you run the risk of destroying it or breaking their morale, and you'll feel like a complete moron for depriving B of anything to shoot at.

===Assault (Charging and Fighting 101)===
*Note that you can charge any number of units, even units you cannot possibly get to with your charge move, as long as they are within 12" they are fair game as far as charge targets go. 
*A charge roll is usually 2d6, which gives you an average roll of 7, a 1/36 chance of rolling 12+, 3/36 chance of rolling 11+, 6/36 chance of rolling 10+, 10/36 chance of rolling 9+, 15/36 chance of rolling 8+, 21/36 chance of rolling 7+, 26/36 chance of rolling 6+, 30/36 chance of rolling 5+, 33/36 chance of rolling 4+, 35/36 chance of rolling 3+ and 36/36 chance of rolling 2+. 
*When you charge all models except the first can be moved in any direction, including backwards, towards an objective, on top of a building or towards an enemy unit you did not charge, the only rule is that the unit has to end the charge move in coherency and more than 1" away from units you did not charge, only the first model must actually engage an enemy unit that the unit declared a charge against. This is effectively free movement you can use for anything, even if you are a shooting unit, this can let you get to where you need to be, just charge a unit with little threat in terms of Overwatch and Melee and you get 2d6" of free Movement. You get an additional 3" of free movement before a unit fights and after it fights, the key different here is that you can end these moves within 1" of a unit you did not charge, use this to your advantage, but those units will fight back, so take care to stay 1" away from melee units. 
*Take care to stay more than 3" away from enemy characters if you don't want to engage them, otherwise they will be able to heroically intervene and move up to 3" and engage you in combat, even if you did not charge them. Many Imperial Knights are characters, meaning they can heroically intervene as well. Some units can heroically intervene 6", Space Wolves and certain Imperial Knights for example. Adeptus Custodes can charge you in your charge phase as well with their jetbikes, so watch out for these things!
*Players go back and forth each picking one unit at a time to fight with, but the very first charging unit always gets to go very first, nothing your opponent can do about that, so pick your first unit to fight carefully, after this your opponent can use a Stratagem to immediately fight with one of their units, after they do or if they don't the player whose turn it is can pick one unit to fight with one at a time until all their charging units have fought, then they can pick one unit they control that has not charged and fight with that, now the other player can choose a unit to fight and this goes back and forth until all units have fought. If a unit is within 1" of an enemy unit at the end of the fight phase it can fight if it has not already done so, so if your opponent uses a Stratagem to fight again and engage your units that have not yet fought, they now get to fight. If a unit is more than 1" away from enemy units and it did not charge it will not be able to attack, take care not to allow your opponent to remove the models with one unit which another one of your units would have liked to fight against. Generally pick the unit with the fewest models within 1" and fight with that first, your opponent will have a harder time removing the models that are within 1" of your 20 Genestealers than your Hive Tyrant. 

====Advanced Notes====
*Sometimes a shooting unit can be as valuable in melee as a dedicated melee unit, most units cannot fall back and shoot. Simply engaging an enemy shooting unit with your transport or shooting unit can hold it up for a turn.
*As a general rule of thumb, you want to break or destroy your enemy in your opponent's assault phase. That way, your opponent does not have a shooting phase before your assault teams move towards their next target.
*Generally speaking, Overwatch is more of an annoyance than a true threat, though certain rules, bonuses, etc. (Tau Supporting Fire/Counterfire Defensive Systems, flamers, etc) can take their toll, especially if you're relying on glass cannon units (Harlequins, notably). Some special "Negate Overwatch" powers exist, but there are other ways to mitigate the effects of Overwatch. Unlike 7th, there is no limit to what can fire overwatch or how many shots. Wyverns, for example, fire their regular 4D6 shots. Granted, they hit on 6s, but this can still hurt. During Overwatch, any ability that lets you re-roll all misses is ''much'' more effective.
**Overwatch takes place before you move your charging unit, and is still subject to normal rules for Line of Sight, cover, etc. Moving a Rhino or other vehicle flat-out to block off models from shooting your chargers is always a valid trick.
**If blocking Line of Sight is not an option, then aim to eat the overwatch. One way to do this is to have a "tanky" unit lead the vanguard. For example, when charging a unit armed with multiple flamers, have a fast monster/walker lead the charge. Heck, throw a Rhino at your enemies before charging with those Assault Terminators.
** An easy way to ignore Overwatch is to charge a model with '''FLY''' from behind LOS-blocking terrain (aka the 1st floor of a ruin if you're using ITC rules) because the model ignores moving through terrain. You do not need LOS to declare a charge, but your opponent always needs LOS to use Overwatch.
*Remember that pile-ins use the same overall rules for charging, and thus any unit must ultimately maintain coherency. When attacking a large spread-out unit, you can negate a lot of its strength by attacking on opposing flanks.
*The ability to quit close combats is a very powerful ability, especially if you have Fly. As long as their initial charge doesn't hit too hard, you can kite them all day with Fly.
*In multiple or extended combats, casualty removals via pile-in are very tactical. By careful removal of casualties you can force enemies to pile-in in the direction YOU want them to.
*You can charge multiple units with a single model; the model just needs to be able to get within 1" of one of the declared units, not all of them, though obviously if they're not within 1" of all the units then the others can still overwatch again later in the phase as they don't have a model within 1" yet. This makes models with a good defense and a big base good for soaking as many overwatching units as possible before sending in your other squads. Transports are perfect for this.

===Vehicle Tactics===
Ever since 8e made vehicles nothing more than a keyword which changes how some rules apply to them, vehicles require no special tactics other than what you would apply to other models unless they fly.

===Morale 101===
A unit loses additional models in the morale phase, in general, equal to 1d6 + casualties taken this turn - Leadership, but cannot lose more models than it has, of course. This means the smaller a unit, the less it needs to worry about Morale - a 1-model unit never needs to roll for it in the first place, since it can't be alive after taking casualties, for example. It also means the expected "further" casualties from morale start at a plateau of 0 where the unit is immune to casualties, followed by an accelerating curve up, then an accelerating curve down, then a linear curve down once the unit is being wiped out in the morale phase, so it loses one fewer casualty to morale with every additional one it took earlier. For example, a 10-model unit with Leadership 6, taking mounting casualties from 0-10, suffers additional casualties in the Morale phase, on average, as follows: 0, 1/6, 1/2, 1, 1 2/3, 2 1/2, 3, 2 5/6, 2, 1, 0. This corresponds to the unit being the following size (on average) after Morale: 10, 8 5/6, 7 1/2, 6, 4 1/3, 2 1/2, 1, 1/6, 0, 0, 0.
*The morale phase happens after the psychic, shooting, and assault phases and any casualties from those phases are added together when testing morale.

===Dice Roll Maths===
*It is almost always better to re-roll dice than to get +1. For instance, re-rollable 4+ has almost a 10% edge over 3+.
**The exception is re-rolling 6's, which is 1/36 worse than 5+.
**Because of how people throw dice, a re-rollable 2+ has a lower chance than math suggests. People tend to use the same rolling motions, which means those dice often end up in the same position ("1" both times). So use a dice tower or roll your dice more thoroughly for a longer period of time in order to increase randomness and adherence to estimated made via mathhammer.
**The only time you want a +1 To Hit instead of a re-roll is with Overcharged Plasma weapons or effects that proc off of 6+'s.
*The average roll on a D6 is 3.5
*The average of 2D6 is 7, 3D6 is 10.5., and 4D6 is 14 (add 3.5 for each die you roll). 
*Picking the highest of two dice adds about 1 (actually .9722....) to the average roll.
*4+ re-roll 5+ is the same as 3+.
*Re-rolling 1s is always equivalent to multiplying your odds of succeeding by 7/6, which means, additively speaking, it's better the higher your original odds are: you'll get an extra success in every 12 dice for a 4+, 9 dice for a 3+, and slightly more than 7 dice for 2+ (actually 7.2).
**Re-rolling all failures has a larger benefit the lower your original odds; you'll get an extra success every 4 dice for a 4+ base, every 4.5 (i.e. 2 successes every 9) for a 3+, and every 7.2 for a 2+.
*The odds of getting a 9 or more on 2d6 is 10/36, a little less than a third (27.78%). Re-rollable, it's a bit less than half (47.84%)
*And, if you're into it, there's [[MathHammer]].
*GW dice are not mathematically fair! This set of mathematical data presumes you are using perfectly balanced casino dice which are. See following for details. http://www.dakkadakka.com/wiki/en/That%27s_How_I_Roll_-_A_Scientific_Analysis_of_Dice
[[Category:Warhammer 40000 Tactics(8E)]]
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