Editing Warhammer 40,000/6th Edition Tactics/Tau (section)

===Allies of Convenience===

'''Blood Angels:''' Sanguinius with his Shield take care of his little friends, especially Stealth Suits who achieve a +2 cover on the open! Beware of flamers though. Yes, you are thinking that "you can not cast psy powers on allies of convenience, only on battle brothers" and desiring to delete this, but wait a moment because Shield of Sanguinius is cast on the Librarian and affect any unit within 6" the Librarian. Hooray for loophole abuse!  

'''Chaos Space Marines:''' Spiky gue'la could provide you a lot of choppy guys to screen you gunline or even kill/tarpit some troublesome enemy squads. Khornate cultists are MUCH better then forgeworld worker gangs for a cheap choppy tarpit, but if you want more, [[Fabius Bile|Fabulous]] khornate marines would wreck some shit. For more dakka, plasmachosen and dinobots would dish out a lot of white-hot plasma on medium range, and deepstriking termicide squad could melta some tanks like fusion commander bomb, but unlike commander they would at least force a lot of fire to their 2+ armored asses before they die. Do note, that you cannot ninja cult squads into troops in allied detachment.

'''Dark Angels:''' You cannot Ravenwing and Deathwing in allied detachment, and DA does not benefit from your beacons (<s>unless porta-rack is taken</s> Porta-racks let you use enemy teleport homers and locator beacons, but not homing beacons.), but they are cheaper than regular marines for gunline, albeit a bit worse in close combat. Also they are like the only army in 40k that could bring more plasma than you. Ravenwing knights rad-grenade launcher when combined with Darkstrider railfinder squad could make miracles.
Of course, Getting a Ravenwing Darkshroud is an extremely viable option, particularly when you sit it above a Bunker that is chock-a-block of Firewarriors. Giving them all free stealth for additional saving bonuses on top of the terrain is a bargain at 80 points. 

'''Grey Knights:''' Can be quite effective. Choppy Strike Squads can be a very effective screen for your squishy Tau. But they will take a decent toll on your points if you want a big enough wall. Alternatively, a Stormraven filled with Terminators can cause quite the stir for your unsuspecting foe, but again, this will cost you a VERY shiny penny.

'''Imperial Guard:''' This is your Gue'Vesa auxiliaries. They are shooty bastards much like your own army, but a bit slower, and can endure more beating (through numbers). Use them like cheap meat shields and moving cover, or place fucktons of tanks and heavy artillery to back up your gunline with even more firepower. That be said, you also could ally with all Forge World special IG lists - Elysians would give you a fuckton of flyers, Kriegers - meatshields that would HOLD THE FUCKING LINE, and Armoured Battlegroup - plethora of tanks, including horrible abomination of cheese what is BS4 Monster Slayer Co-axial Vanquisher of Doom.

'''Necrons:''' They are shooty cover campers, that lay waste on vehicles and die in close combat... just like you. Unlike you they have much more survivability in the open (as they are designed for close range firefights, instead of sniping across the board) pie plates of hate, lots and lots of battlefield cheating rules, some of which stacks perfectly with Tau (HOD with Solar Flare for your nightvision army? Yes, please!), and last but not least motherfucking flyer cheese <s>of scythes</s> croissants. And if you want to screen your gunline with close combat beatstick, they get one too.
*Before allying with Necrons be aware that many of your own models can do the same jobs for less. Fire Warriors shooting is more versatile than Necron Warriors shooting, though Necrons are better at assault with their higher WS, S and T combined with reanimation protocols; Fire Warriors can have Haywire grenades but their use is situational.  Missilesides will outperform Annihilation Barges while Hammerheads and Railsides will outdo Heavy Destroyers.  Monolith guns are not as good as Riptide guns though the Monolith is more survivable and has the portal, so for offence the Riptide, defense the Monolith. The best use for Necron allies is Triarch Stalkers, Doom Scythe and Wraithwing.

'''Orks:''' A maxed out squad with a warboss could give your opponent enough of a distraction to forget those 8 bajillion guns being pointed at them by little blue men and women. Orks can add more fun into the game, as having more meatshields or units with hilarious equipment (Big Mek with Shokk Atack Gun and a suicide Commander can make a fun setup) will make more major lulz throughout the game. Also, Farsight working with Orks. Using the Orks in basically the most obvious way possible (choppy meat shield) works fairly well too in an infantry-heavy army, because it keeps your Tau guys out of CC.

'''Space Wolves:''' Have some nice buffs and fluff to assist the Tau, such as completely bitchin' IC's that can bring a lot of strong units to the table, and can take cheaper assault marines than vanilla SM in the form of neophyte Bloodclaws that can work as a screen for your squishy Fire Warriors. Just remember that they have a tendency to rush into CC, robbing you of further shooting at the squad until either of them are dead.