Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

I still can´t really understand keywords and detachments and specifically the rules allowing/prohibiting stuff. Like, I can´t mix Chaos Daemons and Death Guard (for example) in the same Deatchment. Why not? I can take Death Guard Cultists and/or Poxwalkers in the same detachment as Plague Marines, but not Plaguebearers...? How many keywords must be the same for it to count?

If you're playing Matched Play you can't use CHAOS as your Faction Keyword (p.280), so you'd use DEATH GUARD or NURGLE for your example - but you might lose some Faction Abilities by mixing books / factions.

You can mix nurgle daemons and DG in the same detachment, but you wont gain any detachment abilities. The daemons wont get their locus, and DG wont get their contagions of nurgle. In general, to get detachment abilities your detachment must be pure, only units from the same faction must be included. There are a few exceptions to this, though. All units in one detachment must share at least one keyword, which cant be CHAOS. There are more restricted keywords, but only CHAOS matters here. If the keyword is NURGLE its fine, but no detachment abilities.

p245-246 of the Core Rules has the rules for how Battle-forged Armies work.

As per those rules, all units in an army must share a Faction keyword. This is further restricted by the matched play rules (p280), which state that each Detachment must have a shared Faction keyword, and some Faction keywords cannot be used for this purpose.

In your example, Chaos Daemons and Death Guard share the CHAOS (and possibly NURGLE) keywords. In Matched Play, CHAOS cannot be used as a shared keyword, but you could have a NURGLE Detachment, containing both Death Guard and Nurgle Daemons.

However, using NURGLE as the shared keyword for a Detachment would prevent that Detachment from counting as either a DEATH GUARD Detachment or a DAEMONS Detachment, and any rules which rely on that status would not be applied, i.e. special abilities, Stratagems, etc.

So as long as every unit has <Death Guard> and <Plague Company> keywords it´s fine to use their abilities? Because <Death Guard> and <Plague Company> are the only two faction keywords that doesn´t exist for Chaos Daemons.

I dont understand what are you talking about.

The difference between using units from Chaos Daemons and Death Guard codicies are minimal. I can take a unit of Cultists in the same unit as Plague Marines, both being troops from the same codex and sharing the all the same keywords except <Heretic Astartes> and still all the abilities are usable. Using Chaos Daemons with Death Guard <Nurgle> and (obliviously) <Chaos> is doable but I lose the special abilities from both CD and DG. Why? How many keywords must be the same? Is it keywords or codex that prevents me from using them in the same detachment?


Automatically Appended Next Post:
Is it the lack of <Death Guard> that prevents it?

Detachment rules only work when units in a detachment (or the entire army) are from the same faction. The individual codexes tell you that. DG only get their detachment ability CONTAGIONS OF NURGLE when every unit from your army has the DEATH GUARD keyword (excluding UNALIGNED units). Thats written in the DG codex. If you include Chaos Daemons in your army not every unit in your army has the DG keyword, so no CONTAGIONS OF NURGLE.
The codex daemons says you only get a locus (detachment ability) when your battle forged army includes Chaos Daemons Detachments – that is, any Detachment which only includes units with both the CHAOS and DAEMON Faction keywords. Now, depending on your choice of DG units, that mixed detachment of daemons and DG could still be a valid chaos daemon detachment.

Finally it sank in for me, haha!! Thanks dude!

Just as an addendum- GW has said that if you summon the plague bearers into the battle then you still get to keep your Death Guard abilities. This is because you determine whether you get abilities or not after the army creation step of the game. Since the daemons are not on the detachment list when that step is complete they don't count against any rules.

 p5freak wrote:
Detachment rules only work when units in a detachment (or the entire army) are from the same faction. The individual codexes tell you that. DG only get their detachment ability CONTAGIONS OF NURGLE when every unit from your army has the DEATH GUARD keyword (excluding UNALIGNED units). Thats written in the DG codex. If you include Chaos Daemons in your army not every unit in your army has the DG keyword, so no CONTAGIONS OF NURGLE.
The codex daemons says you only get a locus (detachment ability) when your battle forged army includes Chaos Daemons Detachments – that is, any Detachment which only includes units with both the CHAOS and DAEMON Faction keywords. Now, depending on your choice of DG units, that mixed detachment of daemons and DG could still be a valid chaos daemon detachment.

As you must have the Chaos and Daemon faction keywords, you can not have any Death Guard units in a Chaos Daemons detachment since they don’t have Daemon as a faction keyword.

To quote the relevant rules:

A DEATH GUARD Detachment is one that only includes models with the DEATH GUARD keyword (excluding models with the UNALIGNED keyword).

So, yay, a DEATH GUARD Detachment, what does it do?

DEATH GUARD Detachments gain the Diseased Minions, Infernal Jealousy and Foetid Virion abilities.
BUBONIC ASTARTES units in DEATH GUARD Detachments gain the Inexorable Advance ability.
PLAGUE MARINES and POXWALKERS units in DEATH GUARD Detachments gain the Objective Secured ability.

If your army is Battle-forged and includes any DEATH GUARD Detachments (excluding Auxiliary Support, Super-heavy Auxiliary and Fortification Network Detachments), then when you are mustering your army, you can upgrade any of the following models in your army by giving them a Deadly Pathogen

If your army is Battle-forged, <PLAGUE COMPANY> units in DEATH GUARD Detachments gain access to the following Plague Company rules, provided every model in that Detachment that is drawn from a plague company is drawn from the same plague company

If your army includes any DEATH GUARD Detachments (excluding Auxiliary Support, Super-heavy Auxiliary or Fortification Network Detachments), you have access to the Stratagems shown here, and can spend CPs to use them.

If every model in your army (excluding UNALIGNED units) has the DEATH GUARD keyword, and your WARLORD has the DEATH GUARD keyword, you can, if you are playing a matched play battle that instructs you to select secondary objectives (e.g. a mission from the Eternal War mission pack in the Warhammer 40,000 Core Book), select one of them to be from the Death Guard secondary objectives listed below.

Some rules just require one "pure" detachment, some require your whole army to be DEATH GUARD. If you mix your army too much, you get locked out of these rules.

Note that relics and warlord traits are an exception to this - they only care about what faction your warlord is.