T'au are constantly evolving, innovating and expanding. On the other hand, their caste system is very rigid.
So, aside from changing the caste system, anything goes as long as it serves the goals/will of the ethereals (read: higher good).
As for playing them:
Generally speaking, T'au are shooty, mostly long range. Their Infantry is a bit squishy, battlesuits a bit more resilient.
T'au tend to augment their medium BS with markerlights and use drones as bodyguards (via savior protocols).
Their great weaknesses are the lack of psykers (no cast/deny) and the meelee phase (with some exceptions).
If I was starting T'au, I'd go with a small low points army picked from one of
- all infantry: a few squads of firewarriors (maybe w/DS8 turrets) supported/lead by an ethereal (buffs morale & provides other buffs) and/or cadre fireblade (gives extra shots for pulse weapons), maybe a squad of pathfinders w/special weapons (can also bring interesting support drones) and/or a squad of breachers in a devilfish. Such an army would be more of a horde and gunline-like (except for the devilfish & transported squad ofc.). It can also be a cheap battalion.
- all suits: a commander leading crisis suit squads, maybe a unit of drones (as ablative wounds) or two and/or a larger suit (e.g. vx88 broadside or vx95 ghostkeel). Such an army would be more elite and could be somewhat more mobile.
Most T'au lists I know of use a combined arms approach (infantry + suits).
Aside from devilfishes, vehicles/tanks seem to be more of a rare sight this edition.
Did I mention drones yet? They're good I hear.
The big question lorewise is: Farsight Enclaves or T'au empire?
Farsight Enclaves are a bit non-conformist to say the least.
Edited by Exilyth, 20 October 2019 - 06:41 PM.