I've recently started an ascension campaign set in Deathwatch's Jericho Reach and the party got *very* interested when they discovered the fate of the battleship Execution Eternal noted in Rites of Battle. Short story, it was nearly taken by Tau-smitten traitors, but the warp drive was disabled. It's the site of a year-long conflict between the Tau and the Imperial Navy, who see it as their fight to win and won't let the Imperial Guard near the place. After ferocious fighting, the Tau hold the enginarium with the Navy security battalions in the bridge and crew decks.

The party has been told that offers of help from other Inquisitors have been turned down by the Navy. However, they have good reputation (Imp Navy) and are pretty militaristic with an Ordo Xenos Istvaaanian PC inquisitor. So they've sent their own offer of aid to the crusade forces, the reply to which will come in the next session (this I've already decided upon, not posting it here).

My query is as follows. What forces, weapons and tactics would the Tau Empire be likely to use in a long running campaign to take over a stranded Imperial battleship 10km long? I'm not as familar with Tau as some other 40k forces, but some ideas thus far:

At least some squads of Fire Warriors with pulse carbines. Shorter and more practical than the rifles in the relatively confined spaces. Plus, handy photon grenades for messing up the gue'la. If the Tau have messed with the massive enginarium, the lights may be off over portions of the ship and darklight visors would come into their own.

Pathfinders for extra sneaky goodness.

A few kroot to stalk the shadowy, body-strewn corridors.

Gue'la auxiliaries to charge the enemy. Usually armed with naval weapons such as shotguns, flamers and grenades but officers and traitor storm troopers could easily have hellguns, pulse weapons and more unusual armanent.

Drones. Handy for scouting.

Earth and Air caste for research purposes. This gue'la ship is far beyond their own craft in sheer power and is worth studying.

Larger armour or exotic troops may or may not be appropriate in the confines of a starship (even Imperial) but I'm open to suggestions.

The recent supplement for 'Deathwatch,' entitled 'Mark of the Xenos' has a really helpful section on Tau forces which you could field. My first tabletop army was Tau, and so I have a long lasting soft spot for them - here's what I think might be a likely military response:

• Kroot would be great in enclosed spaces and as swift response counter attacking troops for the Tau forces on the ship. They may also bring Kroot hounds with them for tight spaces with their ferocious attacks driving back naval armsmen, and softening up the enemy before a full Kroot counterstrike. Kroot teams can thus be used for hit and run, or even to hold the upper levels of the enginarium decks where they can dig in and snipe, being a constant nuisance to advancing humans.
• Vespid stingwings, though likely not deployed in a ship to ship action would probably appear in those large engine spaces, where they could deploy from above to take out heavy weapons teams with their crystal pulse weaponry. They would be able to move pretty quickly between slow moving machine parts to hit and run, like the Kroot.
• Don't discount the use of battlesuits (as if you could!). Crisis battesuits, armed with close range weaponry like flamers, burst cannons and fusion weapons would be pretty devastating, although the bulk of these suits makes their use in confined corridor spaces impossible. A more likely option might be stealth battlesuits, deployed with either fusion guns or burst cannons as appropriate. They are more heavily armoured than Pathfinders, but might usefully deploy with them where they can light up on any marker light targetted enemy with surprise.
• It is worth thinking on what the Tau Empire codex says on how Fire Warriors might behave in this situation tactically. Generally the Tau dislike this kind of 'siege' close combative warfare, but "on the rare occasions when the Tau are absolutely compelled to defend a vital resource, they will still apply their traditional techniques. In this case, the Mont'ka (killing blow tactic) is applied as lightning fast forays out of the defences, each aimed at killing the enemy that pose the greatest threat. The Kauyon (patient hunter tactic) is represented by a feigned retreat from the perimeter to draw the attacker into a well-prepared kill zone (Tau Codex page 12)." You could see that ambushing the enemy and crushing them with a quick counter might be the way the Tau would apply these tactics. They might make use of sniper drones on long corridors to blow holes in front-armoured assault troops, and would seed spaces with traps and ready fast moving troops to sweep in and mop up. They are very reluctant to waste Fire warrior troops in pointless attrition with the more numerous forces at the disposal of the Imperium, and this may explain their lack of success or will to really push into the crew decks.
• Another thing worth considering is whether or not there is an Ethereal present (more than likely somewhere?). Without one of the Aun present the Tau would begin to regress, becoming more aggressive and less heeding of their philosophys. They might end up attacking their own auxilaries, like Guel'a, and would be more inclined to counter the enemy into close combat, where they would fare less well. With an Ethereal present they would fight all the harder the closer to their commander the fight came and this character would represent a high priority kill target for a group of throne agents.

Thanks for the suggestions RedMike. I have the Execution Eternal dropped out in deep void, with a number of Imperial and Tau craft hunting each other in the local area. Both launch assault boats and shuttles with reinforcements/supplies and both use fighters and weapon batteries to stop the other doing so. Both sides have lost lesser starships and quite a number of smaller craft haven't made it back to launch bays. So debris and a few hulked ships litter the void for a few thousand kilometres around the battleship.

As for an Ethereal, what's the range of their calming effect? Would it make more sense for one to be on board the battleship under heavy guard, or on a Tau vessel standing off a relatively safe distance? Since one can effect Tau on a world, I'd imagine the range is at least a few hundred kilometres if not thousands.

On the party's resources, they have their own Cobra destroyer with a barracks full of troops (guardsmen level skill and equipment), torpedo tubes and a teleportarium. They're pretty confident the navy will allow at least them on board, but some players have said they are willing to sneak on if necessary. Depending on the navy's attitude, they may or may not get approval to bring their own troops or a deathwatch killteam on board. The latter would not be hanging around with the party if present. Bearing in mind the morale issue, this could get tricky.

Don't be afraid to innovate with the Tau - their greatest strength is their understanding of their technology, which means that they will experiment and adapt technologically where other races wouldn't. In particular, employing never-before-seen patterns and configurations of Battlesuits designed for void combat seems like an appropriate development for this kind of situation.

N0-1_H3r3 said:

That's a very good point. They have had a year of failing to take over the ship. There's time and incentive for innovation.

They will definitely seek to use innovations in technology, which is the big advantage they have over the hidebound lackies of the Imperium. There is no hard and fast rule over the range of an Ethereal's powers, but it is probably unlikely that the pheromone control would stretch across the void of space. There would have to be an Ethereal on board the ship, obviously along with a higher rank battlefield commander, let's assume a Shas'o. This individual, and any Shas'El subordinates might be armed with more exotic experimental weaponry.

The Earth caste, although non-combative, would operate behind the lines engineers, constructing traps and helping to fortify kill zones against assault. Air caste Tau, notabe for their spindly frames, would fly assault craft and some may be stranded on the ship as well. Finally, any Water caste present could be used as intermediaries with Guel'a forces and if necessary as ambassadors in any negotiations with the enemy.

In terms of the party's access; the navy, with their good relationship with the group Inquisitor, I am certain would happily allow them to assist, especially if the role of the Throne Agents could be kept relatively quiet. An assassinaton job would seem the best course for the party given the situation - they will want to do by stealth what the navy has been unable to manage by force. If it came to deployment of the Deathwatch - well, all bets are off as far as anyone else goes. The navy would be forced to stand down once the Astartes deploy - as simple as that. It may sour relations between the navy and the Inquisitor if the Space Marines go inin the long run however.

I didn't think GW had made it clear that it was pheromone control or psyker ability or something else like subliminal audio signals. Or is it a case that it's just the Imperium isn't clear on it?

Traps...mmm yeah, those could work a treat!

Even someone in good steading with an organisation isn't necessarily going to get what they want, when they want. The "Oath Bonded To The Angels of Death" talent suggest a tight bond with a particular Space Marine chapter...and only reduces the penalty to acquire their services at any given time. As for Deathwatch boarding, killteams often infiltrate active battlezones with or without the knowledge of the local forces. With a ship on silent running and a shuttle in a debris field, a team could certainly get aboard without too much risk of detection.

Tau could jury rig the grave plates on the ship possibly. Could be used to cut off corridors or even trap platoons of humans.

Battlesuits if adapted for the void could actually launch assaults on the exterior of the ships hull. Soemthing the Imperium would find hard to do without space marines or adapted armour.

Tau weapons are quite powerful. They might recognise that this could damage the interior of the vessel. Therefore they might have started to use lower powered weapons (possible something with the shocking quality?)

Tau might actually start trying to get the engines working again and move the ship. If I remember my BFG correctly the Tau sometimes tow their vessels when they skim the warp. If the Tau did a similar strategy here....well needless to say an Imperial Cruiser would be easier pacified if inside Tau space without further reinforcements to complicate matters.

New battlesuits for certain, purpose built for void action. Engineering and computer specialists to maintain control of captured areas along with supporting assaults into new areas. Nothing says oh crap like the lights and gravity going out and all the plumbing reversing itself right as the Tau invade a new section of the ship. With the scale of Imperial ships, the Tau shouldn't be approaching this as what we imagine as a traditional boarding action, but more as taking over a space colony. Key weaknesses include life support, power systems, food supplies and maintenance supplies. They should trying to cut the Imperial defenders off from one ore more of these as a method of weakening their resistance.

Who controls the space around the vessel ?

I ask because the side that doesn't have control of space also won't have access to resupply or reinforcements.

Given that the Navy is in a position to not allow the Guard aboard the ship, that suggests that they have control. Which means the Tau don't. Also, if the Tau had even temporary control I can't them staying for a full year. Either they win quickly through overwhelming firepower brought by reinforcements, or they pull out.

Tau Pulse weaponry is only better than a Lasgun while it has ammo. Usually not a problem as the Tau focus on mobility can allow them to leave. But when their escape route and supply line is cut off, then they will run out of ammo (How much ammo do the Tau carry ?). But if you can power the lights, you can recharge a lasgun.

How much ammo would the Tau have ?

Actually forget ammo. What's the situation with their food and medical supplies ?

@Visitor Q

Grav plates, sure, once they figure out how to do it reliably. Most Tau besides the Air Caste are used to gravity, so they'd want to make sure they can turn the grav plates back on at some stage.

Battlesuits on the outside of the hull? Definately the sort of mobility Tau are fond of.

Not so many pulse weapons near the hull perhaps.

It's a good question whether the Tau could navigate the ship with the enginarium but no bridge...

@BlackKestral

Air and Earth caste I suspect would be the likely candidates for voidcraft engineering/computer specialists.

The Execution Eternal is pretty much a beached whale and is bigger than some fixed stations, so that's hardly a strange way of approaching the problem.

@Bilateralrope

The space is contested. Early on, both sides showed up to (re)claim the ship and fought each other to a standoff, neither side ever gaining full control of the surrounding void. The battleship is in the midst of a cloud of debris and a few broken smaller starships. Both sides *can* resupply, but neither is certain of getting any specific flyer in or out.

The Navy isn't keeping the Guard out by force but by politics. The generals might not approve, but they're not going to push the matter with the people who they rely on to move their forces about.

The Imperials definately have an easier time getting supplies, if only because they don't need to bring in as much ammunition for the reasons you stated. As for the Tau staying, they have partial control of a potentially war-winning piece of Gue'la technology. Previous efforts have failed but the Tau adapt and will win the vessel for the Greater Good. Or so they think.

For the record, Inquisitor Kane has been politely informed that he and his personal retinue can board the Execution Eternal but not his armsmen or any Deathwatch kill-teams. It remains to be seen what the cadre will make of this news.

Regarding Ethereals, the Mark of the Xenos discusses the background of one of the Tau heros. In it, the Tau were aware when the last Ehereal on the planet was slain and it was a major blow to morale. Likewise, as the siege dragged on and the Tau regressed, the return of the Ethereals at the head of the relief force was immediately felt by the beleagured defenders. So the "range" of the Ethereals seems to be planetwide, possibly some sort of astro-empathy rather then astro-telepathy.

That means the Tau on board the Retribution almost certainly have an Ethereal with them, although its possible nearby Tau ships could also provide the effect. In contested space, it might be possible for a small Tau ship to lurk while cloaked bearing members of the Ethereal caste. Or you could just say its enough that an Ethereal lead re-inforcement effort re-supplies the Tau on board every few months.

If the Ethereal is on board, he would definitely be a high priority kill target...but an even higher priority capture target. The Death Watch and Inquisition are both extremely interested in the Ethereal caste and any Inquisitor able to provide a live specimen would gain major influence I should think.

As for innovating ship-board combat, I can see all kinds of sneaky booby traps being used by the Tau. For one thing, it doesn't cost actual man-power (which is far more important to the Tau then Imperium) and is a relatively cheap but highly effective and demoralizing force multiplier. Jury rigged Photon grenades turned into mines and booby traps are great ways to go. All kinds of drone ambushes are also alternatives, as are more primitive trap types perhaps inspired by the Kroot. The no-man's land between the warring factions could easily be a nightmare of booby-trapped corridors and chambers housing jury-rigged IEDs or unexploded ammo/ordinance, prowled by Kroot hounds and their packmasters.

Tech-altering weapons would also be an option. The Tau seem to favor precision long-ranged weaponry as this follows their tactical doctrine nicely. Its not unthinkable that you could convert railguns and even pulse weaponry to be much shorter ranged, but with a greater blast effect. For example, I could see a heavily modified railgun being used as a sort of massive blunderbuss weapon being a VERY effective way to clear a corridor of attacking armsmen. Perhaps the pulse guns are modified to fire a more dissipated projectile, losing range and penetration but gaining a Blast or Scatter quality.

I could definitely see the party starting their infiltration attempts into the Tau controlled section of the ship and witnessing or being a part of skirmish. The shouts of "scrap cannon!!!" by frantic armsmen throwing themselves into cover followed by a massive fwoosh as 300 kilograms of sharpened metal fragments fill the corridor. As the blast clears, the surviving armsmen rising up and charging the Tau as their sergeants scream "Get into 'em boys! Kill em all before they can reload! For the emperor and the Retribution!" and the corridor fills with a brutal close quarters fight. Its certainly an evocative setting for a combat oriented game session =).

This sounds like it's going to be a fun game for your players. Firstly someone mentioned above that the Tau Skim the warp, they don't, Tau don't have any kind of Warp Travel.

Let me just see if I have everything Correct, The battle field is an Imperial Naval Cruiser, floating in a debris field of destroyed vessels and other assorted space debris. Both the Tau and Navy have a Nominal hold on the debris field relying small craft to do supply and re-enforcement runs. Area's of the ship are held by both sides with area's contested. Sound about right?

One thing that does seem a little off, Tau view Imperial Tech as backwards and ineffient, so the reasons behind them trying to capture a Cruiser intrigues me. Also if the Imperial Navy thought there was any chance that they couldn't re-claim the cruiser quickly they would just destroy it. Infact if it's so damaged it's going to take a lot of resources to fix, they are likely to steer it towards the Tau lines with the Warp Engines set to overload.

In this instance I would think it's unlikely the Tau would use Kroot on a ship, they are more likely to use Human reserves, probably those that had worked aboard an Imperial ship before.

As for booby traps, that's just mean, but really cool idea. I like the idea that some of the battle suits would have much higher powered variants of the rail gun, designed to penetrate the internal walls, coupled with enhanced sensors on the suits to pick out human body heat and thermal images and such. Through wall snipers. Stealth Suits roaming corridors feeding extra data to these enhanced rail rifles.

There would be no reason that a Kill Team wouldn't get invovled, but it is likely to a specific task, prehaps the Etheral or simply a Tau Weapons cache for the Adeptus Mechanicus, or a whole host of other possible things, this doesn't mean that they will help the players, they may even see the players intervention as a problem.

Hope you and your players have fun......let us know how it goes

Valdek said:

Well, according to Battlefleet Gothic they sort of do skim the warp with their Gravitic Drive .

Valdek said:

I have to disagree. First of all, an Imperial Battleship is more or less a relic in itself and blowing it up without proper reason (short of blowing up a Hive Fleet with it) would not only be treason/heresy for the Imperial Navy and the Adeptus Mechanicus, whereas manpower sent upon the vessel to recapture is expendable at large; secondly the Imperial Navy is a proud bunch and most would rather die then let a ship of the line fall into enemy (or even xenos hands), let alone simply blowing it up without trying any other measure available in the universe.

Valdek said:

I would absolutely assume they use Kroot, as one would expect a lot of close quarter fighting onboard (i.e. in the corridors of) even such a large vessel. Their higher agility and perception would make them even more viable in such boarding actions. Battlesuits with Fusion and Ion Blasters as well as Flamers sounds fitting as well. I would leave Rail Guns at home so to not puncture the hull unintentinally.

A while back our Deathwatch kill team boarded a crippled Tau battlecruiser with the intention of purging and scuttling it (it was parked in orbit over an Imperial world with dead drives). The team boarded by blasting a hole in the hull with their turbolaser and then ramming the Thunderhawk into the resulting hole. The team's Dreadnaught and 2 Devastators remained behind to secure the landing point and the remainder broke into two teams, one for the bridge, one for the prow railgun decks. Astartes vs. Tau in ship corridors is simply NOT a contest! Even when the Tau tried to lay traps and ambushes the marines simply tapped into their cohesion and slaughtered them. Both teams had met their primary objectives in about 20 minutes!

Final tally: Several hundred Tau dead and the ship scuttled. The Astartes Techmarine and Appothecary had each suffered minor hits, but no lasting injuries or losses. They even captured the ship's Etherial and carted him off as a gift to present to the Inquisitor they were coming to the planet to meet as a greeting-gift!

Having the Inquisitor and his retinue do the fighting will probably be more dramatic and nail-biting. Close quarters combat is BAD for Tau and Space Marines thrive under the same conditions.