Tau and Space Marines, battle brothers ?

[Deadlift]

Why ? Where in the fiction is there any background to back this close alliance up ?

I will state I personally love the allies system and have a soft spot for the blue skinned buggers, but before I add an hq and troop choice of them I feel this "need" to justify them joining my Salamanders.

Over to you

[Tzeentch's Dark Agent]

Didn't they join up with the Ultramarines to fight the 'nids at some point?

[Wolfshade]

The Ultramarines fight in blue, and the Tau are blue, they obviously view all their enemies as Gargamel and therefore unit for smurf kind!

Cry Smurf and release the Smurfs of Smurf

[eldargal]

It isn't an alliance. The Allies chart isn't a hierarchy of formal alliances, it is a hierarchy of how far trust extends when it comes to individual battles. So a Tau force and Space Marine force arrive on a world, the Tau to retrieve experimental technology, the Imperium to purge some heretics. Out of the blue a daemonic incursiom breaks out. Both sides still have goals to achieve, they can't achieve them on their own, they trust each other enough not to cooperate to a limited extent on the battlefield. Once the battle is over they go their seperate ways and/or try and kill each other.

Remember the IoM DOES have limited diplomatic contact with xenos races, their xenophobia is very much shades of grey rather than blck or white. For a long time they had an actual embassy of some sort on Alaitoc. Inquisitor Czevak visited Iyanden and the Grey Knights were able to contact the Eldar to have them fetch soulstones from teh hulk of Malantai to prevent more daemonic incursions. The IoM and Tau also have a treaty of some sort in place after the stalemate of the Damocles Gulf campaign.

[Tzeentch's Dark Agent]

There must be a pre-existing reason for their allegiance though?

[eldargal]

Not necessarily. Space Marines stuck on a rock fighting off a Dark Eldar raid when a daemonic invasion breaks out, the choice is work together briefly or be destroyed. They won't trust each other and things will be very tense but they won't act like complete morons an fight everyone at once anymore.

There are some genuine oddities on the allies chart though. Black Templar being happier to work with a race of psychic aliens than the anti-psyker SoB, for example. I get that the BT and SoB might not necessarily like each other much, but less secure working together than with Eldar? I really think not.

[Wolfshade]

I hadn't considered that.
instead of being a grandiose diplomatic statement it is the degree to which each side would trust each other if they face a common enemy.That makes it alot more easy to digest than to say Tau and Space Marines are allies, but they will fight along side each other against a common foe

[Tzeentch's Dark Agent]

Not necessarily. Space Marines stuck on a rock fighting off a Dark Eldar raid when a daemonic invasion breaks out, the choice is work together briefly or be destroyed. They won't trust each other and things will be very tense but they won't act like complete morons an fight everyone at once anymore.

There are some genuine oddities on the allies chart though. Black Templar being happier to work with a race of psychic aliens than the anti-psyker SoB, for example. I get that the BT and SoB might not necessarily like each other much, but less secure working together than with Eldar? I really think not.

It's quite an oddity, I know that some Chapters would not even slightly trust Aliens. (Red Scorpions for example)

[TSINI]

Havent got the rulebook yet, but uneasy alliance against a shared foe is different entirely to being battle brothers, one is how marines and intelligent aliens would view each other, the other suggests 2 forces with shared goals, respect and willingness to lay down your life for theirs...

Some crap about the emperor telling the ultramarines to protect of work with the Tau or some BS

[Wolfshade]

It is but then you would have to assume that if you are playing a more fluffy army that isn't ruled for, you would play within the spirit of it.