It's a simple premise, I hope; let's share our best fights from Dark Heresy, either from the perspective of the players or GMs.
I'll start off with what is probably the best fight scene I've been in, ever. It happened yesterday, in fact. A friend took over my Dark Heresy campaign to run a side-quest as I continue working on my storyline. He has taken us to Arroyo, a Frontier World where Somnius Halbrel (anyone else remember him?) has apparently been lurking since we drove him off of Desoleum. Think a planet of lush Grand Canyons separating tracts of Mojave, full of dangerous local critters, feral jerks and Orks. Next best thing to a Death World. The people are very Mad Max. There are also no functional aircraft at this point in time.
Now, we find out Halbrel is to the south. The train is running to the south, and our aircraft had been sabotaged with no parts available for the next few months. We pick train over driving because it is faster and safer. Or so we think. The train has a tank turret, three autocannons and ten mook guards, as well as the five PCs and four NPCs, not including the goons running the train. We're on the train for two days when going by this gulch. None of us notice the feral boarders who got onto the train until they kill the guy on watch in the front and plant crude explosives on the tank turret, disabling it. We all get up at that sound. We also come out of the gulch, with a grand total of...
Ten pursuit vehicles with three boarders each (one with hunting lance, one with pistol and sword, and one bruiser with an electro-axe).
Ten gun cars with a heavy stubber and gunner each.
Ten motorcycles with autoguns.
One war rig of doom; three stories tall, armed with a harpoon gun, two heavy stubbers, two heavy flamers and twenty boarders/gunners/drivers.
All told, it was seventy-nine mooks, ten elites and one master with a ton of automatic weapons and explosives riding in on either side of the train as the boarders start jumping on and killing crew.
This was versus-
Ten mooks (autogun with bayonet each, three 'functional' autocannon turrets).
Four NPCs (a sniper type, a Castigator wielding Arbites, her sister and a brawler)
Five PCs (Arbites using Plasma weapons, Bounty Hunter with a Webber and a Melta, Sniper with a Needle Pistol and a Surprise!, Tech-Priest with an Omnissian Axe and a Duelist chick with power swords).
Now. The fight begins with a throat cut and a turret disabled, to start. People react to the explosion! Bounty Hunter goes outside to see what's going on, sees the armada of armored vehicles. Snipers go to guard the captain. Arbites runs to the next train-car to support. Tech-Priest rubbernecks behind the Bounty Hunter. NPCs go out to deal with the turret. Two mooks climb into the turret and get attacked by boarders, other mooks start shooting (and sucking) at the attackers, sans one guy who gets a kill.
The next round as vehicles start pouring in to the sides; Sniper goes and gets his shiny, unused missile launcher. Arbites side-arms a krak grenade into a full boarding vehicle and Righteous Fury's them to death; does not cause a pile-up. Bounty Hunter meltas a different vehicle after the boarders get on, no pile-up. Tech-Priest goes up to get rid of boarders with the Duelist, and the NPCs are picking off people they can hit. NPCs repel boarders while four of the mooks die while being boarded; the one left at the tank turret closes it, and the one with a kill gets another! We have about two-dozen bad-guys on the train now.
The BIG RIG shows up! They see the horrible things the meltagun does to their cars, so the harpoon gunner tries to impale him; barely dodged, Chain 1 stuck to train. Bounty Hunter shoots Webber this time, hits a car and cuts their visibility. Sniper continues fetching his Missile Launcher. Arbites tosses another Krak grenade, blowing another vehicle with a double Righteous Fury while moving down the train. Duelist guts two boarders, Tech-Priest guns down the rest in the area with the help of brawler NPC. Other NPCs continue keeping boarders off their side. Three more mooks die while being sucky; turret mook opens the hatch and last mook at the end of the train has THREE Ferals attacking him after he kills the fourth.
Sniper pops out of cover and puts a frag missile almost point-blank into a trio of cars trying to board. Kills one, stops another with the wreckage, third continues. Duelist cuts the chain stuck in the Train. Arbites starts shooting boarders as they climb up the train at him on the second car. Bounty Hunter meltas another car, doesn't destroy it. Tech-Priest turns to deal with more boarders. NPCs continue repelling boarders; brawler jumps off of the top of the train and Mario-stomps a bad-guy. Mook on turret takes the Autocannon and! JAMS IT. Mook in the rear kills another guy attacking him, takes a hit though.
Sniper snap-shots another missile (he reloads fast) and kills another car. Bounty Hunter finishes off a wounded car with a Melta, and dodges the second Harpoon shot his way. Boss gets on the train and shoots the Arbites with a Righteous Fury in the leg; he takes a point of Fatigue due to a lucky roll. Five other boarders surround him and start swinging. He gets the bright idea to drop an entire bandolier of primed frag grenades and jump back to the other train car! He kills three bad-guys but biffs the jump, falling between the cars onto the connecting platform. Tech-Priest Hallucinogen Grenades a couple cars at once; a lot of craziness ensues. Duelist jumps onto one of the cars attacking. Dumb Mook does not clear Autocannon jam, gets shoved out of the turret by Sniper NPC. Super-mook kills ANOTHER bad-guy. Other NPCs fighting; brawler is boxing with a bad-guy.
Sniper gets jumped by some boarders, no more missiles. One rolls a 100, gets his axe stuck in the wall. Boss enemy messes up the Tech-Priest with some mook allies as they jump cars in a charge. Arbites blasts a car with his plasma pistol and starts climbing back up the train. Duelist swings into the boarded car and kicks the driver out, hijacking the vehicle. Bounty-Hunter takes cover, does not get shot with the Harpoon Gun this round! It hit the Dumb Mook, spearing him with an instant kill and dragging him off the Rig. Super-Mook kills his fifth enemy in the back.
A couple vehicles crash from hallucination effects or other problems; Sniper Needle-Pistols someone in the eye, Arbites climbs up the train in time to Maximal Plasma Pistol with Righteous Fury into the Boss enemy's back, killing her instantly. Duelist runs over a motorcycle with her new ride. Tech-Priest starts killing boarders. Bounty Hunter Meltas the giant war rig's pilot. Brawler NPC gets Harpooned! He fails his dodge, but with cover and armor... Takes 0 damage! He is literally pinned to the wall with the harpoon lodged in the side of his armor. NPCs get shot up some more as they fight a bunch of gun-cars. Super-mook moves up the train to get in on the fun. Sniper NPC gets the autocannon working again.
The war rig crashes into the train, knocking people down, some people falling off, etc. Arbites jumps between the train and rig, seeking to take control before bad things happen; fails, is hanging off of the train's side by one hand. Sniper finishes off his last, fallen opponent and buckles in. Tech-Priest nearly falls off the train, scrambles to his feet. Duelist starts muttering swear-words over the micro-bead as they ram another enemy car. Bounty-Hunter, his melta empty, goes to reload from safely inside the tilting train. Super-Mook kills another bad guy, the six remaining vehicles (two bikes, two gunner-less gun-cars and two pursuit vehicles without any boarders) peel off and end their role.
Last round, the train is being tipped over by the giant war-rig dragging and pulling with the massive chains from the two harpoons stuck into the train. My Arbites, hanging from a rail by one hand, Quick-Draws his plasma pistol and with a -60 penalty puts a Maximal plasma pistol shot into the main chain, breaking it and causing the war-rig to peel off and tumble, saving the train from being toppled! (And from crushing him, he would have been rolled over had it happened.)
Grand-total; nine mooks dead, one mook injured, two NPCs injured, four PCs injured with one partially damaged train V.S. One boss dead, ten elites dead, seventy-two mooks dead, six escaped, one captured, with one war-rig, eight motorcycles, eight gun-cars and eight pursuit vehicles destroyed. The nameless mook now has a first AND a last name, and has been recruited from his old job. When asked if he would like to work for the Inquisition, his response was, and I quote, "**** this planet, I'm in."