Editing Warhammer 40,000/Tactics/Imperial Agents (section)

====Troops====
*'''Veterans:''' Sternguard Veterans as Troops, with the same basic wargear as the Sternguard and the special ammunition the deathwatch is famous for.  As for as the groups of power armoured units in this book go, they're more expensive than the Sisters, less expensive than the Knights, and far more customizable than both.  To start off, you're forced to get at least 5, but unlike many other armies, all 5 of them can get special weapons and wargear, and this is where the massive amounts of customization come into play.
:If you want them to be good at semi-long ranged combat (24"-36"), then grab a few missile launchers, some stalker pattern boltguns and call it a day.  Seriously, their special ammunition for the bolter can reach so far it's not even funny, allowing you to outshoot the Tau while ignoring their armour at the same time.  Note that you should never buy Storm Bolters, it's just a bad idea since they cannot use special ammunition, and that is a huge bonus to just squander for a very minor possible benefit.  If for whatever reason you absolutely have to take it, always replace the CCW of the Marine with it, and this goes for buying long-ranged weapons in general, losing the CCW will not hurt you in any way, shape or form, losing the boltgun will, unless you're replacing it with a weapon from the Special/Heavy Weapons lists (where replacing it is mandatory, but you can get cool shit there).  Unlike the Storm Bolter, the Heavy Bolter is an option you might consider getting, it's only 5 points more than the Storm Bolter, puts out more shots than your specialist ammo allows for, and usually at a higher Strength and AP value too, though it's by no means a must-have.  You could also give one of the Marines a Storm Shield and stick him up front, just in case you're worried about any long-ranged AP3.
:For mid-range combat (8"-24") you've got a some nice options, most of which are completely outshined by the all-purpose Frag Cannon.  Despite their price Frag Cannons are well worth getting, and anyone who's T5 and can resist the close-range ID will still go down to a barrage of S7-S9 AP4-AP2 shots, after you use them to pop whatever Transport your target happens to be hiding in of course, just make sure they're properly supported and the enemy can't focus all of their fire on the squad before they've done their job.  Getting a squad with Frag Cannons into position is one of the harder things you can do with the Deathwatch, especially if your opponent knows what you're doing, and isn't stupid.  The Infernus Heavy Bolter can be useful here too, being strong enough and putting out enough shots to warrant its price tag for an Assault weapon that's usually a Heavy weapon, and the Heavy Flamer provides great protection against enemy units that somehow got a little too close, though that's more of a mulligan in this case.  If you're worried about units getting that close, or if you want to close in yourself, then you should have just paid the extra 5 points and gotten another Frag Cannon.  You also still have your bolters and their special ammunition, and in this case you don't want the Stalker Boltguns.  Heavy simply isn't going to offer as much of a benefit as the mobility a Rapid-fire gun can offer.
::Note too that there are a few ways to get Frag Launchers into position on Turn 1, you can use the Inquisition to get Master of Ambush and set up your guys already within killing distance, or you can buy one of several transports to get them there.  Corvus Blackstars, Chimera's, Sororitas Rhino's (the latter two courtesy of the Inquisition), all of them will get you there without costing too much, at the same time they'll also offer extra protection to your troops.  This is nice because Frag Launchers are fucking expensive, being three points more than another marine!
::Do note as well that if mid-ranged AP2 is all you're after and you've only got one specific 2+ save target in mind, then just go for Grav-guns or Plasma Guns, both of which benefit Greatly from the Mission Tactics and Aquila Doctrine, and cost a little less than the Frag Cannons.
:For close range weapons, Heavy Flamers are a nice option, being far cheaper than the Frag Cannon (and the Infernus Heavy Bolter), shotguns can do wonders for softening down an opponent for assault, as well as acting as a good deterrent for the squad getting assaulted themselves (the amount of Template weapons the Deathwatch can field is disgusting).  Once again Frag Launchers shine here but you need to be more careful with them, while their Template fire is devastating the squad's going to become a very big target, and you can only Overwatch once.  If you get charged by something you didn't want to use the Wall of Death on, then you're kind of screwed when the squad you did want to WoD decides to join the party too.  This is on top of not needing quite that much Wall of Death anyway (you do not need 2D3 per marine), Heavy Flamers can give you all you needed while keeping your points down.  The Infernus Heavy Bolter is debatable here, mostly because of its Assault Heavy Flamer.  If you know you're up against blobs and want to move marines to help counter a player who knows how to position blobs so that Heavy Flamers aren't so bad, then go for it.  Even though Frag Cannon's are only 5 points more, you might need that AP4 (and Rending doesn't always cut it).
:For close combat you've got a ton of options, and feel free to mix and match.  If you know you're going to be against some TEQ's then grab a power axe/fist to go alongside some Lightning Claws.  Get a Storm Shield so that you can live long enough to make it to close combat in case you know that the opponent's get their fair share of AP3 weapons.  Always make somebody a Black Shield if you know they're going to Assault, his special rule comes in handy more often than not, and you should definitely give him something like a Power Fist or a Thunder Hammer, as he'll almost always be Wounding on 2+ while Aquila Doctrine lets him re-roll the 1's.  A Xenophase Sword for the Sergeant can also be a good idea, but only if you know what you're up against.  Many opponents you want to have re-roll their Invulnerable saves are going to have 2+ armour, though you'll be glad he had it any time you go up against ones who don't.  Heavy Thunder Hammers can also be a great idea, and you might as well take one instead of the generic Hammer if you were planning on getting one anyway since it's only 5 points, and being two-handed isn't going to hurt you since the generic's have Specialist Weapon.  S10 AP2 is fantastic, but don't always count on Pulverize, you simply don't have the attacks necessary to get it to happen whenever it's most convenient. 
::Note that having a Xenophase Sword can and will also cancel out some of the re-rollable Invulnerable save's some armies can get.  You can't re-roll twice, so if the first save is successful, and the second save is a failure, then that's it, the second save remains a failure and their bonus for re-rolling saves no longer has any benefit.
::Deathwatch in assault can also benefit greatly from an allied Priest as he can make the whole squad live a lot longer than they had any right to, especially if you've got a Storm Shield soaking up a lot of damage from AP2-AP3 weapons.
::There are also a few different ways of actually getting Deathwatch assault squads into assault, however the most obvious one is to just take a Corvus, and then ally in somebody who can either bring the Skyshield Landing Pad, or ally in an Astropath (it's not like you weren't going to need Prescience on something that you were allying the Deathwatch with already).
:Finally, remember that no matter their loadout, a Deathwatch Veteran Squad is always going to be a target, so make sure you've got other squads covering their ass and picking of any potential threats (such as AP3, Strength 6+, and any sort of transport popper).  Their cost can skyrocket, and losing them before they've done their job can easily cost you the game.