ok….still trying to wrap my head around this.

it states on page 219 of the core book that Chapter specific squad abilities are only useable by members of the same chapter. kay….got it.

on page 5 of the Errata, it says to add “Battle-Brothers may activate the
Chapter abilities of their own Chapter even if the squad leader is not of the
same Chapter, but these abilities will still only affect the Battle-Brother and
any members of his Kill-Team that belong to the same Chapter.”

then….on page 228, oath-taking it says "In addition to listed Codex Squad mode abilties the kill-team will also have access to their leader's Chapter Squad mode abilities"

SO….do I have this right?

example: The squad leader is a Dark Angel Tactical Marine. While in squad mode, he activates his Chapter Squad ability SUSTAINED SUPPRESSION (dark angels). Because he is the leader, all members of the kill-team in squad mode can benefit from this regardless of chapter.

Standing next to the leader is an Ultramarine Devastator, he also wishes to use a Chapter Squad Mode ability LEAD BY EXAMPLE. But because he is NOT the squad leader for this mission and there are no other Ultramarines in the kill-team only he can benefit from its effects.

vyrago said:

Squad and solo mode is the hardest part for many of us to get

From Page 4 of the Errata:

Gaining Squad Mode Abilities (page 219): The sentence “Depending on the squad leader’s Speciality and Chapter, he will have access to a different election of abilities which his Kill-team may then use during the course of the Mission” should change to “Depending on the squad leader’s Speciality, he will have access to a different selection of Codex abilities which his Kill-team may then use during the course of the mission.”

From my reading (and help in clarification from other forumites), the specifically removed the portion referencing the Leader's Chapter, meaning that the rules apply as normal, irrespective of whether or not they are Squad Leader.

So, if the Squad Leader is a DA Tac Marine, when in Squad Mode if he activates Sustained Suppression, only those that are of the Dark Angels chapter can benefit from the ability. The workaround for this is the Tac Marine's special ability where he can make a Command check to allow those not of his chapter to benefit from his Chapter Abilities. Other work arounds are in Rites of Battle as additinoal talents you can pick up that let your Kill Team use other chapter abilities.

Right. Unless you're a Tactical Marine (with the right ability) acting as squad leader, you generally can't 'share' the benefits of Chapter-specific squad mode abilities with those not of your chapter.

For instance, our group includes: Ultramarines Tactical Marine (Brother Antenor, Leader), Blood Angels Librarian (Leonatos), Black Templar Apothecary (Luther) and a Space Wolf Assault Marine (Actos).

Brother Antenor can give everyone the benefits of Lead by Example ( am I remembering the name right?) if they are within range, assuming he passes his Command test. However, Leonatos decides to go crazy and activate his Blood Angel offensive squad mode ability. He spends the cohesion but no one else benefits from this. If brother Actos was a Blood Angel, for instance, then he could benefit from their Chapter abilitiy as well.

If Brother Luther was the leader of the Kill-Team instead, brother Antenor could still spend the cohesion for Lead by Example, but only he would benefit from it.

oaTh-Taking

The Adeptus Astartes hold their oaths to their Primarch, the Emperor, and their brothers above all other things in the galaxy. Such pledges of valour given to their Primarch, Battle- Brothers, and the Emperor are a common part of a Battle- Brother’s existence and often take place before embarking on a Mission. Oaths can come in many forms, and different Battle-Brothers may make different oaths before a battle depending on their focus for that Mission. Before embarking on a Mission, the players may choose one oath for their Kill-team which will last for the duration of the Mission. All oaths have a prerequisite Career Path and may only be chosen by the Kill-team if their current leader meets this requirement. An oath will then provide the Killteam with a group benefit as well as a selection of Squad Mode abilities, any or all of which may be activated during the course of the mission. In addition to the listed Codex Squad Mode abilities the Kill-team will also have access to their leader’s Chapter Squad Mode abilities .

core rule book pg 228