Some interesting ideas here, but I'm not sure you've really addressed any of the core design issues that are causing tau to have such a bad time. It seems like your goal may have been to give them a raw
power boost, and you ended up adding a lot of complicated rules in the process? A few things that jumped out at me:
Tactical drones unit is deleted, all drones become more of a marker then a real model. I only have rules for the basic 3 now, see the markerlight section. Basically, a unit with a drone has the damage of the first failed save they make set to 0, and the drone leaves. A shield drone has a 5+ to remain, while a marker drone just adds reroll 1s and a gun drone gives reroll all overwatch. Accompanying drones otherwise work the same, price wise. Tho only at start of game.
I'm guessing the problem you were trying to solve here was savior protocol cheese. Am I right? In which case, there are probably a lot of simpler ways to solve that problem that don't involve invalidating/removing a datasheet. For instance, you could just make savior protocols a shield drone-only thing and maybe remove shield drones from the list of options in a tactical drone unit. Or change shield drones to work in a similar fashion to what you've described below and just keep them out of the tactical drone squad unit.
Markerlights: at the start of your command phase, roll a number of dice equal to the number of marker light wargear options are in play. Set these markerlight dice aside. During your shooting phase, while declaring a unit to shoot, you may use any number of markerlight abilities by spending your dice (though each unit may use each ability only once per phase)
When you spend a die, you use either the "Target lock" or "Support utility" effect of a die of that value. (Some characters might modify the value)
1:reroll one hit roll
2:reroll one wound roll
3:reroll all hits and wounds for missile type weapons, and they hit on BS (seekers, smarts, etc. Its a lot. Maybe too good?)
4:enemies can not add cover while saving
5:roll 3d6, closest enemy unit takes a mortal wound on each 4+ (targeted bombing run)
6:a successful wound becomes penetrating, and invuln saves cannot be made against it, but it deals -1 damage
1:heavy weapons count as assault weapons whenever beneficial
2:add a missile turret within coherancy. It becomes it's own unit, and acts as normal. (Just a gun with a few wounds.)
3:add a markerlight drone to the unit. While present, the unit rerolls 1s to hit. When this unit fails a saving throw, the damage becomes 0 and a drone is removed from its unit.
4:unit adds a gun drone. A unit with a gun drone rerolls hits on overwatch. (See above also)
5:unit adds a shield drone. When a unit fails a save, it becomes damage 0. Then, roll a die. On 1-4, remove drone. 5+ the drone remains.
I feel like you're getting relatively little improved gameplay for the number of special rules you're presenting here. You've got 11 distinct buffs (that have possibly confusing crossover with each other). You've got the markerlight dice mechanic itself (which involves rolling dice for some reason?). You've got a variation on unit summoning which is going to call for its own clarification. Also, it seems like your proposal lets units with markerlights grant markerlight benefits even if they don't have line of sight to the enemy, which seems odd/contrary to fluff.
The pet idea for markerlights that I've been mulling over is something like this:
* At the start of the tau command phase, each markerlight in your army can put a markerlight token (MT) on a unit they can draw line of sight to. (No need to hit; a miss still adds to the targeting data.)
* Until the end of your turn, you can spend MTs to fuel "Markerlight Stratagems" that target the unit they were placed on. Basically, MTs are command points that fuel off-brand stratagems.
* Have those Markerlight Stratagems be whatever. +1 to-hit. Ignore cover. Fire a seeker missile at normal BS, etc.
* At the end of the Morale Phase, remove all your MTs from the table.
This is sort of similar to what you're pitching, but you only have to remember the stratagems you're interested in using against a given target rather than tracking potentially 11 different effects. Having to assign MTs in advance creates a bit more interesting choice and (imho
) represents the nature of markerlights better than simply using the best possible benefits against your first target, then the best possible benefits against your second target, etc. It feels like you're actually planning a firing solution. Probably best to avoid drone summoning as a markerlight mechanic.
And Master of War: at the start of your command phase, choose either montkaor kauyon. Each unit within 8" of a battle suit commander gains the following benefit. The benefits grow stronger the longer you remain in the same stance, tho you are free to shift each turn.
1: if a unit has advanced, it ignores all penalties due to advancing and shooting. In addition, it may reroll 1 hit roll.
2:units that advance, move, or fall back count as stationary instead. In addition, reroll wound rolls of 1 within half range.
3:units may roll an additional d6 when advancing or falling back, adding it to their movement speed. In addition, units who did so have -1 to getting hit
1:if a unit moved less then half its love characteristic, it may reroll wounds of 1
2:if a unit moved less then half of its movement characteristic, it may reroll all hithits
3: if a unit remains stationary, it gains objective secured(or counts as 2) and gains a 5++ invuln.
This is kind of neat, but I again wonder if you're really getting enough improved gameplay to warrant the extra complexity. With this, you'd have to track which of 6 special rules you have on a given turn on top of which 11 markerlight rules a given unit is benefitting from, and again there seems to be a bit of overlap between those benefits. Also...
* It seems a little weird to tie this exclusively to battlesuit commanders. I know that's how it currently is, but surely a fireblade ought to be able to coordinate a montka or kauyon.
* 8" is weird as 40k
usually uses increments of 3". 6" or 9" would feel more consistent. But honestly, tau have walkie talkie technology, and a kauyon or montka seems like the sort of thing the entire army should be in the know about; not just the guys standing next to the commander's suit. Plus, castling up is one of the thematically worst things to happen to tau, so encouraging it with more auras seems like a mistake to me.
* As written, you only gain a given set of buffs instead of stacking them with the earlier versions. Which means that you might actually end up with less useful buffs for staying in a stance. A railhead gunship, for instance, is more likely to fail to hit than fail to wound against many targets, so it might actually prefer Kauyon 1 vs Kauyon 2.
* Tau are supposed to be mobile. The current kauyon rules restricting their movement is a design mistaken in my opinion. Continuing to encourage tau to hold still here seems like a mistake for the same reasons.
Here's my pet pitch for montka/kauyon:
* It becomes your army-wide ability (similar to doctrines) instead of an aura.
* Declare that you're performing either a montka or a kauyon at the start of the first game round.
* Montka and Kauyon become two-stage benefits meant to represent the initial and secondary stages of the plan. You may declare that you're entering the second stage during any of your own command phases. Once you enter the second stage, you can't go back.
Strike to Kill (Stage One) - Declare a single enemy unit to be your Primary Target when you declare your Montka. Each time a tau unit is selected to shoot at the Primary Target, you may reroll a single to-hit roll. If at the start of your command phase your Primary Target has been destroyed, you may immediately declare a new Primary Target. While in this stage, tau units ignore the to-hit penalty for advancing and firing assault weapons.
Let's Go Home (Stage Two) - Ranged attacks against Tau units that fell back or advanced in the previous Tau movement phase suffer -1 to hit.
Lie in Wait (Stage One) - You may immediately redeploy up to 3 Tau units when you declare your Kauyon. While in this stage, tau units add 2 to their armor saves instead of 1 when benefitting from light cover against attacks made from more than 15" away.
Spring the Trap (Stage Two) - Tau units may reroll failed to-hit rolls against targets that began the current player turn within engagement range of one or more tau units. While in this stage, tau units may shoot after falling back but take a -1 to-hit penalty when they do so.
So my goal for Montka here is lean into the concept of focusing down a key target and then switching to a more defensive mode once you start to favor mobility over offense in the latter half of the game. It gives every unit in the army a bit more offense against a single target each turn (a nod to the 7th edition tau decurion), but it doesn't lock everyone into a bubble around the commander. Once you start putting more emphasis on survivability than killing power, you can switch to a defensive buff that gives up some of your offense.
With Kauyon, I'm trying to model the idea of springing a trap. Making your units more durable against ranged attacks will encourage the enemy to get in close (and then probably charge), but getting into melee with the tau might actually set your units up for a more lethal reprisal on the following turn. Plus, letting suits go back to shooting after jumping out of combat makes them a fair bit scarier. And again, the benefits here encourage you to stay in terrain but don't lock you into a bubble near your commander.
If you wanted to keep some sort of commander-specific ability that interacts with Montka/Kauyon, I'd probably let them switch back to Stage One after switching to Stage Two (but maybe not let them switch back to Stage Two again after that).
Random other wishlist items for Tau:
* Bring back Jump-Shoot-Jump for battlesuits. It was one of the defining mechanics of the army for years, really helped with their identity as a mobile army, and would probably be way less annoying this edition than in the past thanks to the smaller size of tables and increased mobility of many units. This would also give them a way to hop on objectives.
* Kroot could do with a modest raw
power boost. Give them an extra attack or two and the option to pay points to upgrade their movement, strength, or toughness stats to reflect their diets. Maybe let the shaper choose from a list of special rules harlequin/exarch style. I wouldn't mind seeing a heroic intervention option on that list to reinforce their role as counter-chargers for their shooty blue pals.
* SImilarly, vespid make sense as an expendable, deepstriking shock assault units. Upping their melee profile a bit would make sense, and giving them some sort of charge-out-of-deepstrike mechanic might help them in that role.
* I'd love to see some strats or fireblade power options for disembarking after a transport moves and/or re-embarking after shooting. Sort of like certain guard and GSC
strats. I love the idea of mobile infantry tau using their devilfish to deliver troops to key positions and then protecting those troops as they flee the scene.
* The ethereals' current aura seems a bit contrary to fluff (fire warriors acting more watery/earthy/airy is supposed to be taboo), and most games you stick to earth and/or fire all game. I'd rather replace it with a fearless aura and maybe something similar to the eldar spirit seer's spirit sight mechanic. Basically, have tau freak out and get extra murdery at anything within 12" of the ethereal. How ever would you live with yourself if you let something happen to your ethereal?! Maybe even make it a melee buff to turn tau from trash in melee to merely subpar. This has the added benefit of making ethereals on the front lines make a bit more sense. You're walking around wielding a melee weapon so you have an excuse to get close enough to the enemy to drive your mind controlled sla-er... loyal comrades into a protective rage.