Notable Codex Changes: (not comprehensive)

Numerous point cost adjustments. Chaos Vindicators, Chaos Predators, and Helbrutes can be taken in units of 1-3 with similar benefits to the loyalist versions. Helbrutes have their attacks characteristic normalized with Vanilla Marines, and in full units of 3 gain the Deep Strike rule and go into a rage every turn (similar to the Mayhem Pack in the dataslate). Maulerfiends and Forgefiends can also be taken in units of 1-3 and gain +1 WS and +1 BS respectively at full size. Mutilators are now Heavy Support.

Marks of Chaos are broadly the same apart from cost changes, but Mark of Tzeentch now gives a +5 Invulnerable save and three of them have the following additional benefits:

*** Psykers with the Mark of Nurgle, Mark of Slaanesh, or Mark of Tzeentch may roll up to half their powers on their respective table, and manifest warp charge for powers on that table on a 3+.

Apart from the models the rules have been adjusted considerably. All Chaos Marines (Chosen, Possessed, Raptors, Havocs, Oblids, etc), Helbrutes and Daemon Princes (not Chaos Spawn and Cultists) now have the Chaos Allegiance rule. Each unit individually picks an allegiance, so unlike Chapter Tactics your army can have units with many different allegiances in the same detachment. The only restrictions are that you must have one unit of Troops with the same allegiance as your Warlord (Formations excepted) and both units lose all benefits if you join another unit without the same allegiance .

*** Note: Khorne Berzerkers, Noise Marines, Plague Marines and Rubric Marines are all Troops ***

*** Veterans of the Long War is now free, but exclusive to the Black Legion Allegiance ***

Black Legion: [Abaddon the Despoiler is Black Legion]

*** Veterans of the Long War: +1 Leadership and Hatred (Imperials).

*** Vengeful Strength: Characters gain +2 Strength in close combat.

Renegade Warband: [Huron Blackheart and Fabius Bile are Renegades]

*** Selfish Pride: Furious Charge. Can reroll failed Morale, Fear and Pinning checks.

*** Merciless Corsairs: Characters can choose to double their Attacks characteristic once per game.

World Eaters: (Mark of Khorne only, Khorne Berzerkers and Blood Brethren are always World Eaters)

[Kharn the Betrayer is World Eaters]

*** Insane Bloodlust: Add +D3” to max charge range. Automatically pass Pinning checks.

*** Fury of Khorne: Characters gain the Rampage special rule.

Emperor’s Children: (Mark of Slaanesh only, Noise Marines and Blissriders are always Emperor’s Children) [Lucius the Eternal is Emperor’s Children]

*** Martial Grace: Hit and Run. Fleet.

*** Vicious Excess: Characters gain the Rending special rule.

Death Guard: (Mark of Nurgle only, Plague Marines and Plague Wardens are always Death Guard)

[Typhus is Death Guard]

*** Diseased Bulk: Immune to the Poisoned special rule. Automatically pass Fear checks.

*** Plague Arsenal: Flamers, Heavy Flamers, Frag Missiles and Grenades have Poisoned and Rending.

*** Aura of Decay: Characters cause enemy models in base contact to suffer -1 Attack (to min of 1).

Thousand Sons: (Mark of Tzeentch only, Rubric Marines and Corvidaes Covens are always Thousand Sons)

[Ahriman is Thousand Sons]

*** Favoured of the Deciever: You may reroll Invulnerable save results of 1.

*** Infernal Armory: Heavy Bolters, Reaper Autocannons and Autocannons have Inferno Bolts.

*** Sorcerous Premonitions: Characters can reroll a single to hit, to wound, saving throw or manifesting die once per game turn.

Alpha Legion:

*** Coils of the Hydra: Infiltrate. Alpha Legion characters may always join units of Cultists prior to deployment.

*** Headhunters: Characters have Acute Senses and can bestow the Sniper rule upon a friendly Alpha Legion unit’s Bolters/Combi-Bolters if they are within 6” during the Shooting phase, provided that friendly unit hasn’t moved.

Iron Warriors:

*** Siegemasters: Tank Hunters.

*** Shredder Bolts: Heavy Bolters, Frag Grenades and Frag Missiles have the Shred special rule.

*** Iron within Iron Without: Characters gain the Feel No Pain rule. Warpsmiths have +1 to repair rolls on friendly vehicles.

Night Lords:

*** Murderous Talents: Reroll 1s to Wound in Close Combat. Lightning Claws have the Rending rule.

*** Lords of Terror: Stealth and Fear.

*** Gutter Fighters: Characters cause Instant Death on a wound roll of 6 in Close Combat.

Word Bearers:

*** Blessed by the Gods: Units get to roll on the Boon Table whenever they kill an enemy unit in close combat, with all models benefiting from the result (reroll Spawndom and Dark Apotheosis). In addition, psykers count as Daemons for the purposes of using Malefic Daemonology powers.

*** Fanatical Devotion: Characters gain the Zealot special rule, and if they are a Dark Apostle they grant their unit +1 Attack.