Rites of Battle
If your going to be playing Deathwatch this is a must have, even with the high price tag.
Going to Fantasy Flights website and checking out their write up about it (http://store.fantasyflightgames.com/productdetails.cfm?SKU=DW04 ) you'll find 3 tiny paragraphs, and I do mean tiny, your probably going to want to Ctrl+scroll wheel to get them up to a size that not killing your eyes! Yes they do give a accurate if not vanilla description but they certainly DO NOT give this book justice.
Here's a chapter by chapter breakdown of the book. Be warned if your not a 40K fan there's going to be several parts of this you won't totally get.
The book starts Chapter I: Deathwatch Origins with rules to creating any existing chapter (existing as in 'not in the core rules' but wrote about in some 40k book or such) or even a chapter of your own. This break's it the whole way down to such things as Chapters Hero's of legend, Home Worlds, Livery and Heraldry tables. Two of the most amusing are the Chapter Name Adjective and Nouns tables where you could come up with cool names like White Paladins, Millennial Champions, and Imperial Devourers...oh wait that doesn't sound to much like a loyalist chapter name! Regardless there's 37 Adjectives and 55 Nouns and if for nothing else their good for ideas.
The Imperial Fists are fleshed out across eight pages for us to put into our games along with lots of Successor Chapters; Novamarines, White Consuls, Black Consuls, Mortifactors, Genesis Chapter, Consecrators, Angels of Redemption, Angels of Absolution, Fleash Tearers, Lamenters, Blood Drinkers, Knights of Blood, Crimson Fists, Hammers of Doom and Subjugators. Each has about a page of info and history that's a nice Space Marine resource.
Chapter II: The Call of War is filled with Deeds and Distinctions, good and bad. These are give so that during character creation you can spend some of your starting experience on your Marines past and why he was chosen to be seconded to the Deathwatch. From my following list of the types you'll get a good idea of what the six or seven under each title could be. Deeds are; Chapter Deeds, Campaign Deeds, Valorous Deeds, Specialty Deeds, Deeds of Disdain. Distinctions are; Command Marks, Combat Marks, Determination Marks. If you don't find what you want there they tell you how to make your own and give you four examples.
Like there are for Dark Heresy, there are Advanced Specialties that your Marines may take. In the most basic way these are Skill/Talent/Trait lists that you train in that would replace your normal Rank progression table. These's are; Black Shield, Champion, Chaplin, Dreadnought, Epistolary, Forge Master, Keeper, Kill-Marine, Watch Captain and Veteran. Yes, I typed Dreadnought and they give you some good ideas about this too. One suggestion is that if a player ends up becoming a Dreadnought they should have a regular marine too so the Dreadnought doesn't show its armored hide in every game.
Chapter III: Expanded Wargear does not disappoint with everything from Graviton Cannons up to a breakdown of each Mark of armor and more Armor History tables. Space Marine Armor is as legendary as the Marines themselves. There's allot of 40k background out there that mentions how unique and individualized a Space Marines armor becomes after centuries of action, the single Armor History table in the Deathwatch Core Rules book was great and really brought this background to life. Here 3 more are to add to insure more variety in your players armor.
Chapter Relics and Deathwatch Relics finish out Chapter III. These are special gear that can be requisitioned by the players. All the rules are included encase the players are stupid enough to lose one too.
Chapter IV: Vehicles does the best job of the 3 rules sets (Dark Heresy, Rogue Trader and Deathwatch) to finally get vehicle into the game. This doesn't just have droppods to Thunderhawks in it, this includes Warhound Titans too (and yes there are a million Land Raider variants listed!). Chaos gets a few pages from fighters right own down to Defilers. The Tau lover will not be disappointed in the five and a half pages of Xeno's flying thing'ies.
Chapter V: Honour or Death (Not Honor, Honour. Is that how the British spell it? Remember 40K is a British game, not American) gives a breakdown on how to award your players Renown, and how to lose it too. The Honours section breaks down many of the classic Imperial Honours for us. From how to get a Crux Terminatus on up to the Machina Opus. Twelve Honours are listed along with rules for creating your own.
Requisition is revisited in this book followed by Imperial Assets. Imperial Assets are things/people/armies that the party can spend their Requisition points on. From High Altitude Bombing Run's to getting a Sequestered Temple Assassin(who can use one of them!). Unless your naturally inclined to be disappointed, you won't be.
The chapter ends with two pages of Advanced Solo and Squad Mode that seemed like they should have been in the Core Rules and fell on the floor sometime before printing.
Chapter VI: Watch Fortress Erioch gives you the history of the Watch Fortress along with important areas that could end up being adventure sights. The chapter then gives you twelve NPC and eight prisoners of the Watch fortress along and several adventure seeds with each of the NPC's so you can put them right into your game.
I think that one of the challenges of running a long term Deathwatch game will be trying to make the game something more then "go there and kill this, go here kill that". This chapter has four pages of adventure ideas, Erioch Operations, unfortunately two-thirds of the adventure ideas aren't more then the standard Kill-Team 'mode normale'.
The two pages of Artefacts of the Omega Vault you'll find spark off all types of ideas and wil leave you wishing it had been pages and pages longer. The chapter ends with Beyond Erioch: Regions of the Jericho Reach giving you seven more adventure areas to expand your game into.
A mention should be made about the Table of Contents and the Index. Deathwatch: Rites of Battle has both and they both work too!! Yeah that might not seem like a big deal to some of you but if you've been gaming for any amount of time then you've seen what I've seen. Having both and having the page numbers actually take you to where you want to go is a big deal in the gaming world, great work Alex Davy (Editor).
My biggest complaint that I can muster up, less the cost, is that there is no master weapons nor master vehicle tables at the end of the book! Come on guys/girls for the price couldn't you give me four more sheets of paper with all the Wargear and Vehicles stat's in one place? (had to put the girls part in there, Andrea Gausman is in the credits for Additional Writing. Look guys a woman that knows a little about 40k!)
In closing, if you own a copy of Deathwatch you'll want a copy of Deathwatch: Rites of Battle. Its really that simple, go buy your's today.