Covering both the Rogue and the Drifter, this book looks at those characters who have forsaken a conventional 'career' and chosen to live outside normal society. Rogues are the criminal element, having made a conscious decision to support themselves by illegal means; whilst Drifters can be anyone who has chosen not to accept the structured life a regular career offers, but lives in an unconventional - but legal - manner. Other Drifters may have failed to find legitimate employment and have adopted a wandering lifestyle and may upon occasion turn to less-than-legal means to support themselves.
There's an interesting discussion on the various laws which pertain in the Traveller universe. Some are based on universal acceptance that a given act is wrongful: murder, violent assault, rape, theft... just about everyone agrees that these are unacceptable acts. Others are based on whatever code of law is in force where you happen to be, each planet will have its own laws which govern the way in which those there should behave. And then there's Imperial Law, which generally concerns itself with what happens between planets, and which applies to every sentient being within the Imperium. For game purposes, Rogues are those who commit crimes like piracy, smuggling, theft and being part of criminal organisations - there will still be murderers and rapists, but nobody in their right mind really wants to play one!
The first section covers Scoundrel careers. Presented in the standard fashion, they are every bit as skilled as those who have chosen the 'straight and narrow' way, and indeed not all of them are inherently villains although some are and others sail pretty close to the line. Specialist intruders, smugglers, members of organised crime groups, pirates, scavengers, wanderers and even barbarians (people who come from a primitive society but have somehow found their way off-world into the black and into Traveller society. Along with the normal selection of benefits that accompany these 'careers' there is another consequence that criminal acts attract: incarceration (after arrest and trial, of course). There's a couple of new skills too: forgery and security - both as useful for those attempting to keep criminals out as they are for criminals trying to gain access to where they ought not to be.
The next section looks at Criminal Organisations in considerable detail. Whether you want to join one, have to interact with it or have set out to destroy it, here are all the details (and, of course, plenty of tables) to create and run them in the game. Several examples are given as well, to use as inspiration or to encounter during play.
Next comes a decidedly criminal activity: Piracy. This is rarer than you might think, particularly given the constraints of Jump travel, but it does exist. Some are opportunists who just take advantage of a ship in difficulties or just one that has become isolated, others are more organised and set out deliberately to commit acts of piracy, and there are a few who actually capture and steal whole ships rather than rob them. There's a system for providing appropriate targets for pirates to prey upon and the necessary game mechanics to adjudicate a pirate attack - and advice for those who'd prefer not to be their prey on measures to take to keep them safe. There are also notes on those who would deliberately hunt pirates, and on likely loot.
Following this, the criminal action moves planetside with a section on Intrusion. This takes you right through a heist from initial research and preparation. It's much more fun to play through but if for some reason you do not want to there is an abstracted system to resolve it all with a few die rolls. There is a vast array of security and other technology to play with and notes on actually running a heist should your party decide that they want to pull one off. Computer hacking gets its own extensive discussion too. This section ends with a sample target suitable for both physical and computer intrusion attempts.
Next comes the Smuggling section. There's always someone who wants what he is not supposed to have wherever he is... and consequently there's always someone else who will supply that something at a price. Herein you will find customs checks and starport security measures (always fun for tripping up unwary parties who aren't even trying to smuggle anything), and a selection of adventuring ideas with a smuggling theme.
So you have been stealing or smuggling, you now need the next section on Fences and Illegal Goods. This is jam-packed with the necessary mechanics to enable the disposal of ill-gotten gains to garner the credits that are (presumably) the ultimate aim of committing the crime. This is followed by a section of Equipment... perhaps that's where the party will spend their credits. It's mostly tools, weapons and ship modifications for those who'd engage in piracy or smuggling; and it's followed by Tramps and Thieves, a section on the sort of vessels such villainous types - or character parties, of course - might use. Oh, and an inspection ship or two as well.
The final sections are Belt Mining, Odd Jobs - a selection of adventure ideas - Scavengers (about investigating derelict spaceships or even worlds for what valuables you might be able to find), Gambling and Con Jobs (more rules for employing either in your game) and Lost Worlds, the places from which Barbarians come.
As a survey of the scummier side of the galaxy, a peep at the underbelly, this is useful. Even if your party are not self-styled Ethically Challenged Merchants, it's likely that at some time they will encounter those who regard the law lightly. If there's much criminal activity in your games, consider adding both this book and Adventure 2: Prison Planet to your bookshelf - the latter has far more comprehensive rules for a justice system as well as a lot more detail about gaoling miscreants!