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

==Special Rules==
*'''Combat Squads:''' Can split a single full-sized unit into two smaller units ''before'' deployment. Works just like it always has, but more unit types can do it (e.g. Centurions). While MSU is better, it does give Space Marines a unique way to circumvent the Rule of Three or detachment limits. Now they just need to have spammable units worth Combat Squadding.
**With the introduction of Shock Assault (See below) there is worth considering the use of some of the older tactics, back when a Tactical Marine was worth more than just a bolter. One such tactic was to put your guns in one squad and your melee in another, using the ranged weapons to soften up a target then the melee (basically a sergeant either a power weapon or fist) to finish off or better yet to tie up the target unit and finish it off (hopefully) during the opponents turn, denying them a turn at shooting and forcing them to basically waste their melee of chaff. You can also put the sarge in the ranged unit with a combi weapon for a total of 3 bolters, 2 special weapons and a heavy weapon for a makeshift dev squad.
*'''Defenders of Humanity:''' AKA ''Objective Secured''. If your army is battleforged, all Troop units in detachments consisting solely of Space Marines get this ability. When such a unit is within range of an objective it controls that objective even if there are more enemy models within range of that objective, unless they also have a similar ability. It allows your Troops to seize objectives from enemy non-Troops; enemy Troops ''will'' outnumber you.

===Angels of Death===
*'''And They Shall Know No Fear:''' Re-roll failed morale tests. Not going to come into play that much with your generally good Ld scores, but given how punishing Morale can be it's still a good way to ensure your units don't run off, especially for your already small-ish unit sizes & 2W Primaris. And Apothecaries cannot revive models who fled instead of being slain.
*'''Bolter Discipline:'''  Models using a Rapid Fire bolt weapon can double their number of shots (i.e. ''rapid-fire'') if at least one of the following conditions is met. They don't stack (no triple or quadruple shots if you meet more than one condition). The conditions are:
**The target is within the weapon's half range (normal Rapid Fire).
**The model is {{W40kKeyword|infantry}} and every model of its unit remained stationary during the previous Movement Phase. ''If a Devastator's Heavy Weapon marine moves, the Sergeant cannot use Bolter Discipline on his boltgun''.
***It gives your marines the option to commit to those objectives instead of having to get close to the enemy. Factions like T'au may have long ranged small arms, but Space Marines are the only army that can rapid fire from full 24"-''30"'' away.
**The firing model is a {{WH40Kkeyword|Terminator}}, {{WH40Kkeyword|Biker}}, {{WH40Kkeyword|Centurion}}, {{WH40Kkeyword|Dreadnought}}.
***This right here is the good shit. Footslogging terminators now have a significantly improved threat capacity, bikers are somehow even more deadly fast than they already were, and both Centurions and certain types of dreadnoughts have access to hurricane bolters, AKA 12 shots apiece.
*'''Shock Assault''': A brand new buff for Space Marines, if a unit with this rule charges, gets charged, or performs a Heroic Intervention, models in the unit add 1 to their Attack characteristic until the end of the turn (meaning +2A if they can fight twice like with a stratagem). Like Bolter Discipline before it, this will be available to all flavors of Space Marines (including all three of the Chaos varieties), and gives the generally lackluster melee of most Primaris infantry and chainsword assault marines a little bit of a boost. Killer on units with power weapons like Terminators. Also means foes have to be a bit more careful about charging at Tacticals and such to tie them up, more so if you use larger units, and that they can assist in a melee in a pinch. 
*'''Combat Doctrine''': Feel like it's 7th edition all over again. Each of the three Combat Doctrines gives an AP-1 buff to different weapon types in your armies (non-cumulative with buffs from other sources). You have to use each Doctrine in order, starting with the '''Devastator Doctrine''', and once you switch there's no going back, so pay attention to the rhythm of the game. Your ''army'' gains this if ''all units in it'' have this rule, meaning taking a Guardsman Battalion or even a single Assassin CP'd in right before the battle would prevent the SM detachment from getting this rule, but allied SM detachments are ok even from a different chapter.
**On top of that, Chapter supplements give First Founding Chapters (and their descendants) a Specialist doctrine that is a bonus active on top of the regular doctrine. Bringing chapters with different specialist doctrines prevents either from getting theirs.
**These nifty rules will make your marines more efficient killers, but their rotation makes them predictable - devastate -> advance -> assault. Savvy opponents may try to break LoS to force movement penalties on your heavy weapons, rush for melee while you're still under the ranged doctrines, then fall back when you're finally under the assault one, scale buildings, etc. As such, don't be predictable yourself. Remember, you don't need to switch doctrines on the same turn they become available: surprise drop pod a target turn one or advance your infantry under cover of Devastation while your enemy remains confined to their hiding spots turn 3, what have you. The doctrines are as follows:
*#On Turn 1, your army will always start with the '''Devastator Doctrine''' turned on, giving all your Heavy and Grenade weapons the extra -1 AP so that you can soften entrenched infantry and cripple enemy vehicles from afar in preparation for your advance. Remember the first points of AP are the most important ones: AP-2 Heavy Bolters and Assault Cannons are more noticeable than AP-4 Lascannons. Do keep in mind the plethora of sniper rifles and Heavy Flamers (Incendium/Inferno/Flamestorm cannons) are Heavy Weapons too. The boost to Grenades matters only to Intercessors for the most part.
*#On the 2nd turn you switch to '''Tactical Doctrine''', shifting the boost to your Rapid Fire and Assault weapons. Be it to close the distance to the enemy or because your vehicles are about to give their last, this mostly passes the ranged baton to your infantry. And a bolt rifle going from AP-1 to AP-2 is more noticeable than a lascannon going from AP-3 to AP-4. Storm bolters and auto bolt rifles work wonders here. 
*#On the 3rd or 4th turn you shift to '''Assault Doctrine''' (you MUST change to assault on the 4th turn) giving the extra AP to your Pistol and Melee attacks. Don't. Forget. Your. Pistol. The first point of AP is the most important one - chainsword/CCWs benefit the most, while AP-4 on a sword can become excessive.
**As of the 02/27/20 FAQ, you MUST change from Devastator to Tactical on turn 2, and then change to Assault on turn 3 or 4. This will force you to keep at least a few units that are capable of fighting in CQC, as you can no longer just bum around in Devastator or Tactical doctrine and persist on blasting things from across the map.

===Forge World Special Rules===
*'''{{W40Kkeyword|RELIC}}:'''  No Battle-forged Detachment may contain more {{W40Kkeyword|RELIC}} units than non-{{W40Kkeyword|RELIC}} units within any given battlefield role (except for Lords of War; you can take one without needing another LoW first, but this only applies to the first such LoW taken). Also unlocks the '''Relic of Ancient Glory''' Stratagem for use. 
*'''Stratagem - Relic of Ancient Glory:''' At the beginning of your Fight phase, choose a single friendly {{W40Kkeyword|RELIC}} unit. All friendly {{W40Kkeyword|ADEPTUS ASTARTES}} models within 6" of the chosen {{W40Kkeyword|RELIC}} unit may re-roll the first failed hit roll of the phase.

===Chapter Tactics===
Chapter Tactics are special rules based on the {{W40Kkeyword|<Chapter>}} keyword that will affect '''every''' unit in a detachment except for {{WH40Kkeyword|servitors}}. To benefit from Chapter Tactics, your army must be battle-forged, and all units in the detachment must be drawn from the same {{W40Kkeyword|chapter}}.
*Servitors are specified to never gain a Chapter Tactic ''despite having the keyword'', but nobody cares about Servitors because they're shit.
*Super-Heavy Auxiliary Detachments also don't benefit from this, so if you want your Raven Guard Thunderhawks to get free cover, you need to put one in a Supreme Command Detachment at the least.
*A reminder that {{W40Kkeyword|<chapter>}} Ultramarines is not the same faction as {{W40Kkeyword|<regiment>}} Ultramarines, even if both faction keywords are "{{W40Kkeyword|Ultramarines}}". It is, however, a sign of the person trying to pull that stunt being [[That Guy]].
====Successor Tactics====
All Successor chapters that don't already have associated Chapter tactics must make their own.
It's the fourth edition all over again, once more you're allowed to create a bespoke chapter tactic for [[Your Dudes]] by combining any 2 of 18 available options, or use a First Founding chapter's tactics. The available options are listed below: 
*'''Inheritors of the Primarch''': Sacrifice the ability to take a second successor tactic in favor of directly copying a First Founding Chapter Tactic (from Codex: Space Marines, so no copying Blood Angels etc).
**As this still excludes you from taking named characters from that First Founding Chapter, the only reason to ever choose this is when you want a Forgeworld named character and his detachment to have a First Founding Chapter Tactic. Like giving the {{W40kKeyword|Astral Claws}} the {{W40kKeyword|White Scars}} trait so they can charge after advancing [[Red_Corsairs|like when renegade]]. Or if you just want to use the Chapter Tactic without the primogenitor's color scheme. 
** Additionally, pick if you find the full benefit of the parent CT better than a combination. Notably, you can't replicate any individual Chapter Tactic as all of them have at least one element that is unique to them.
**The only restriction is that, IF your chapter's primogenitor is known, IF you use Inheritors of the Primarch it would need to be from their parent chapter. Examples: the {{W40kKeyword|Novamarines}}' parent chapter is the Ultramarines, so you can't use Inheritors to give them the White Scars' trait (because that's not their parent chapter), and you can't give any chapter the Black Templars' CT (because that's not a First Founding chapter). 
*'''Bolter Fusillades''': Re-roll hit rolls of 1 when using bolt weapons. Not only frees your Captains from babysitting line squads so they can focus on the big guns, but it also means you can switch your HQ towards Lieutenants, as anything with bolt weapons is effectively inside a Captain's aura. Keep in mind the Lt's re-roll is statistically identical to the Captain's (better for anything that automatically hits, but worse for anything that hurts you on a 1; neither one affects the odds that a successful hit is a 6 or that a successful wound is a 6).
*'''Born Heroes''': Characters with this tactic can do Heroic Interventions from 6" instead of 3". Pretty terrible outside Supreme Command Detachments, but it's good there. 
*'''Duelists''': When making melee attacks against enemy {{W40Kkeyword|infantry}} or {{W40Kkeyword|biker}}s, ''unmodified'' hit rolls of 6 auto-hit and auto-wound. Explicitly incompatible with the ''Whirlwind of Rage'' tactic, sadly. ''Doesn't work on Cavalry because GW likes to pretend Wolf Riders don't exist; can't blame them''.
**Duelists works better the tougher your target is, although it's somewhat limited in that Infantry and Bikers don't tend to exceed T5. The bonus is better than Whirlwind of Rage when you need a 5+ to wound (DG/Custodes), equal at 4+ (CSM/Orks) and worse when you wound on a 3+ (IG/Eldar/Tau). This also means anything better than a Power Sword would be better used by Whirlwind of Rage, so, unless you want something specific like a melee Primaris chapter that fights T5 enemies, pick Whirlwind. Take note of the combo with Incursors knives... .
*'''Fearsome Aspect''': -1 Leadership to enemy units while they're within 3" of any of your units.
**Situational, but can be combined with other debuffing abilities, such as Reivers' aura, to provide an effect like Night Lords PLUS another chapter tactic, because this is only half of your trait. ''Night Lords, eat your hearts out''. 
*'''Hungry for Battle''': +1" to the advance or charge roll. Amazing for melee units and also pretty good if you want to spam Assault weapons. Has no synergy with bikes or anything else that doesn't roll to Advance (like anything with Supersonic), but at its most noticeable on slow things trying to advance or deep striking things that want to charge right now - you'll definitely notice this tactic's impact on cataphractii terminators, for example.  
** Gets really crazy with the Master of the Vanguard warlord trait for +2" move and advance. Gets even crazier, borderline illegal, with Lias Issodon for +3" to move and advance. 
*'''Indomitable''': You can't lose more than one model from a failed Morale roll. Half of the Dark Angels CT. It can be okay for big units if you want to maximize the effectiveness of Stratagems, but it's not likely you'll fail morale tests to begin with.  
*'''Knowledge is Power''': Psykers with this tactic can re-roll "any or all" rolls of 1 when casting or denying. Half of the Blood Ravens tactic. If you're taking a Supreme Command with 3 Librarians for some reason this is good; ''don't'' take this if less than a third of the Detachment consists of Librarians.  
*'''Long Range Marksmen''': +3" range to all ranged weapons. Your marines get to engage enemies from their own deployment zone, taking better advantage of Bolter Discipline. Furthermore, it's amazing for flamers, which gain 11" range and become able to be used right out of a deepstrike, as well as being almost impossible to avoid by melee units. It also makes meltaguns noticeably easier to use, and while half-range abilities only gain a 1.5" boost, this is enough for Grav-guns and Combi-gravs to double-shoot after deep striking, which makes them a lot less terrible.  Also, don't forget this applies to your grenades as well - 9" frag, krak, and shock, and 7" melta, is enough that you'll want to consider throwing a grenade more often when firing Overwatch.
*'''Master Artisans''': A ''unit'' with this tactic can re-roll a single failed to hit roll and a single failed wound roll each time it shoots or fights (including overwatch). Half of the Salamanders' CT. Units with a few weak weapons benefit most, but few strong is better than many weak for this. Amazing for pretty much any unit, with the standard Salamander caveat that it's a lot better the fewer attacks per unit you have - always go MSU with this. 
*'''Preferred Enemy''': Pick one of the following factions: Aeldari, Tau, Heretic Astartes, Tyranids, Orks, or Necrons. Re-roll hits with melee weapons when attacking them if you charged, were charged, or made a Heroic Intervention. Fluffy, but bad for [[WAAC]] lists unless you are building for one specific opponent; Heretic Astartes are the most popular of these factions and Orks are guaranteed to get into combat with you, but you can get re-rolls for hit rolls cheaply in other ways.
*'''Rapid Assault''': Advancing no longer incurs a -1 penalty on firing Assault weapons. It's okay if you spam Assault weapons (especially meltaguns on bikes), but this tactic needs to be combined with something like Hungry for Battle to make it work. 
*'''Scions of the Forge''': Units with damage tables count their wounds as doubled when calculating the effects of damage. 1/3 of the Iron Hands CT. Good for heavily mechanised lists. 
*'''Stalwart''': When rolling for wounds against your models, natural rolls of 1 or 2 always fail, regardless of any modifiers or abilities the attacking unit might have. Makes your units somewhat better against plasma and other S8+ weapons. The other half of the Blood Ravens tactic.
*'''Stealthy''': Count as being in cover when at least 12" away from enemies. Half of the Raven Guard's tactic. By the time the enemy gets close enough to ignore this bonus you'll be within range for an easy charge. Good for gunlines, especially Vehicles and Flyers; meh for other types of units.
*'''Stoic''': +1 Leadership. Half of the Ultramarines CT. Skip it unless you need it for a very specific plan - it's usually fundamentally garbage compared to Indomitable.
**Stoic is better than Indomitable in the instances where the unit fails by EXACTLY ONE.  However, Space Marine normal leadership, unit size, and ATSKNF means that this happens...  quite a bit more frequently than in might in other armies.    
*'''Tactical Withdrawal''': Units with this tactic can charge after falling back. Roughly 1/4 of the White Scars' tactic. Amazing for melee oriented armies, allowing you to trigger Shock Assault whenever you want.  Generally speaking, best on a unit with {{W40Kkeyword|FLY}} (especially Inceptors), since you can fall back, shoot, and then charge back into melee.
**Wasted on Intercessors and Infiltrators, who can get the equivalent of an extra melee attack without needing to risk overwatch just by firing their bolt pistols; better on Incursors thanks to their knives. Only really works on Troops if you can make them fight twice, if they don't have pistols or you're using another unit to shoot their target between withdrawal and charge, so take it for your heavy hitters instead.
*'''Warded''': 5+ Feel no Pain versus mortal wounds only. Half of the Black Templars' tactic. Situational, but useful if your meta is full of armies [[Tyranids|who]] [[Thousand_Sons|spam]] [[Death_Guard|mortal]] [[Eldar|wounds]].
**All mortal wounds, not just those from psychic powers; this is basically Armour of Contempt but always active, all the time and not restricted to vehicles. A character about to die can fail to save a regular wound, and pass it onto a Company Vet as a mortal wound to try to save it again. A vehicle that fails a plasma roll has a chance to not lose a wound.
**What tries to counter TH/SS? Mortal Wounds SPAM. Well now your TH/SS are 2+/3++/5+++, simple as.
*'''Whirlwind of Rage''': When making melee attacks for a unit that charged, was charged, or made a Heroic Intervention, unmodified hit rolls of 6 score an additional hit. Explicitly incompatible with the ''Duelists'' tactic, above.
**Unlike Duelists, mathematically the Whirlwind of Rage bonus constantly behaves as +1WS (one that also affects WS2+ models), irrespective of chances to wound and not limited by keywords. Plus, its bonus is better than Duelists against targets you wound on a 3+ or less, meaning both your anti-horde and power weapons benefit. Do note that, unlike Duelists, Whirlwind only works in the first round of combat, not that anything you were fielding was planning on staying in melee for longer than that.