In a month or so, I will send my players to the Eye of Terror and of course that they will have to defend their void against an invasion. I just want to hear some ideas about the best way to defend your void. Thank you.

Keep rolling!!!

Wizard of Oz said:

Assuming the geller field holds up the vessel will likely be assaulted on all sides by warp entities. Once you decide that warp entities have breached the hull and boarded you can simply boil it down to a boarding action roll with the knowledge that not much in a 'ratings' arsenal (shotguns and billy clubs?) can harm them. If its a limited incursion that'd be a great chance for the players to save the ship. First they have to know what is happening, you can make the incursion as obvious as you want but if they don't know about it the vessel might start suffering from possessions and murders as the warp entities start eating their way through the crew and reanimating their dead bodies. Perhaps a 'Day of the Dead' across Deck 5 would be fun.

Against more mundane foes, well, you could have every crewman (or at least, every PO or Able Spacer and above) issued with an armoured void suit to be donned when you go to General Quarters, then deliberately vent the compartments (Components) that have been reached by the enemies. Pretty callous tactic, but it'd probably work most of the time. Alternatively, you could deliberately fire the maneuvring thrusters as the boarders get close, maybe even deliberately vent your plasma (power) conduits over them, or directly into a penetrated compartment. Sure, you'll take casualties and a morale hit (very few crewmen are amenable to a plasma bath), but very few things are going to survive being trapped in a compartment as it's flooded with star-hot engine run-off. And lets face it, if you're being boarded by stuff that tough, you're probably well and truly up the creek without a paddle in a leaky kayak anyway...

Hexogrammic wards would be nice, Sisters of Battle might help...

Though when going into the Eye of Terror...have some high up npc recommend your pc's to preserve a single round for themselves, too ward of possession so to say.

Redundent Geller Field, perferibly archeotech. Acolyte navigators to if you can find them. Barrecks filled with faithful, well armed solders. And lots and lots of prayers to the Emperor or Omnissiah, your pick.

An additional layer of hexagrammic wards surround the bridge and machine room might be usefull in case the crew becomes possessed...oh, and reinforced brigde access door in case you possessed crew decides to barge in.

Entering the Eye of Terror should almost suicidal, since your characters are the heroes of the story they should have a chance to survive or die a glorious heroes death.

Perhaps you allow them to BURN a fate point to ward off possesion...for a while...