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In my preparation for the King of the Cape tournament, I need to review and really learn ALL the varied rules that I need to remember for the Tournament and how better to do that rules revision, than so share them in a Hive post?

So let's look at the rules and the strategy of the Space Marines!

In the tournament I will be playing Space Wolves, the viking-like space warriors who have a extremely different way of waging war compared to the other Space Marines. There is a grand variety of Space Marines, from the disciplined Ultramarines, the stoic Imperial Fists to the raging Blood Angels and fanatic Black Templars, all the Space Marines have at least some base rules in common.

The core of those rules is the following:

ANGELS OF DEATH

Space Marines are amongst the finest warriors in the Imperium.

This unit has the following abilities, which are described below: And They Shall Know No Fear; Bolter Discipline; Shock Assault; Combat Doctrines.

This means that on a Space Marine's datasheet, they will hav ethe "Angels of Death" keyword and for that one line, they have each of those rules.

Let's look at them!

And They Shall Know No Fear

Space Marines stand unafraid before the terrors of the galaxy.

Each time a Combat Attrition test is taken for this unit, ignore any or all modifiers.

Usually, when squads take damage, they are more likely to flee. One or two Space Marines left over from a 10 man squad will continue on as though they are still a full unit in other armies!

Bolter Discipline

To a Space Marine, the boltgun is more than a weapon - it is an instrument of Mankind’s divinity, the bringer of death to his foes.

Instead of following the normal rules for Rapid Fire weapons, models in this unit shooting Rapid Fire bolt weapons make double the number of attacks if any of the following apply:
The shooting model’s target is within half the weapon’s range.
The shooting model is INFANTRY (excluding CENTURION models) and its unit Remained Stationary in your previous Movement phase.
The shooting model is a TERMINATOR or BIKER.
For the purposes of this ability, a Rapid Fire bolt weapon is any bolt weapon with the Rapid Fire type.

Rapid Fire weapons are a kind of assualt rifle. Usually you get double the shots at half range. As you can see, Bikes, Terminators and stationary troops taking aim double their shots at maximum range!

It ads that the half range rule still applies.

In my army this only really matters to my Grey Hunters with Bolters.

Shock Assault

The Adeptus Astartes are elite troops who strike with the fury of a thunderbolt. Few opponents can withstand this onslaught.

Each time this unit fights, if it made a charge move, was charged, or performed a Heroic Intervention this turn, then until that fight is resolved, add 1 to the Attacks characteristic of models in this unit.

I have been out of the game a while so I speak under correction here, but the core rules should give most trools and units an additional Attack on the charge into the enemy. Space Marines instead get this when they charge or are charged by the enemy!

A Heroic Intervention is when a squad or tank is charged near a Character (the Captain or some such hero) and the Character will move in to join the fight! In that moment, the Character will also gain an additional attack on that charge.

Combat Doctrines

And here comes a massive amount of rules that is frankly a lot for me to remember and changes the pace at which I need to fight as I go along.

Check this out:

When the Adeptus Astartes fight, they employ a set of combat doctrines to eliminate the enemy. After pounding the foe with heavy weapons, warriors advance to lay down a hail of bolter fire before charging forth with chainswords roaring to finish the foe.

If every unit from your army has the ADEPTUS ASTARTES keyword (excluding AGENT OF THE IMPERIUM and UNALIGNED units), this unit gains a bonus (see below) depending on which Combat Doctrine is active for your army. During the first battle round, the Devastator Doctrine is active for your army. From the second battle round onwards, at the start of the battle round, you can change which Combat Doctrine is active for your army, as follows:
If the Devastator Doctrine was active for your army during the previous battle round, you can change it so that the Tactical Doctrine is now active.
If the Tactical Doctrine was active for your army during the previous battle round, you can change it so that the Assault Doctrine is now active.

So this means, you start the game with an advantage to all your Heavy weapons (and Grenades but they are hardly ever thrown in the first turn) in the Devastator Doctrine.

After that you can choose to move forward to Tactical Doctrine. Thus, should you be reliant on Heavy Weapon firepower, you can just stay in Devastator Doctrine.

Once you are in Tactical Doctrine you can only move forward to Assault Doctrine or stay in Tactical. There is no going backwards or chosing which one you want. Knowing the game, there will probably be armies or characters that can change that!

Devastator Doctrine

The Codex Astartes explains in detail the strategic value of overwhelming firepower applied to key targets at the optimal time in order to eliminate threats and create tactical openings.

While this combat doctrine is active, improve the Armour Penetration characteristic of every Heavy and Grenade weapon that models in this unit are equipped with by 1.

Armour Penetration basically lowers the defending model's armour roll. In the game you need to roll a dice to Hit with your shot. You then compare Strength of the Weapon against the Toughness of the person hit by the shot. You then roll to Wound.

Then, the defender gets to roll an armor save, they roll to see if the armor stops the damage coming through. You roll a 3+ for Space Marines usually, thus a 1 and 2 the wounds go through, but 3, 4, 5, and 6 would mean that no damage comes through.

With an AP -1 weapon, a Space Marine has a 4+ armor save. If shooting with a -1AP Heavy Weapon whilst being in the Devastator Doctrine, it would be -2AP and thus their armor save will only be 5+!

Tactical Doctrine

As the warring armies close upon one another and vicious firefights erupt, the Codex lays out strategies for swiftly seizing the initiative and combining versatility with firepower.

While this combat doctrine is active, improve the Armour Penetration characteristic of every Rapid Fire and Assault weapon that models in this unit are equipped with by 1.

Same as about, but for Rapid Fire and Assault guns. This means the short range firepower, espeically when used in conjunction with Bolter Drill, allows Space Marines to lay down killer fire!

Assault Doctrine

The Codex Astartes leaves no doubt that the killing blow in most engagements must be delivered with a decisive close-quarters strike. It presents plentiful tactical means to achieve this end.

While this combat doctrine is active, improve the Armour Penetration characteristic of every Pistol and Melee weapon that models in this unit are equipped with by 1.

Finally, from as early as Turn 3, you can go into the Assault Doctrine! Same as before but only with smacking the enemy with weapons in close combat!

This is where Space Wolves want to be!

Thank you for reading this post and learning a bit about the RULES of Warhammer 40,000 with me! If you have any questions, please feel free to ask!

Cheers!
@zakludick

Hive South Africa