Sure, you can have a regular, heroic adventuring party. But why not create your own band of thieves and create a guild? Sounds pretty awesome, right? But how do you go about doing it actually in the game? That's where Assassins, Rogues, and Outlaws comes in. It's a new sourcebook all about that up on Kickstarter now.
From the campaign:
Assassins, Rogues, and Outlaws will include everything you need to play a party of criminals in 5th ed. Have you ever wanted to start your own Guild? Or have your gang run the streets of a city. Maybe you have wanted to grab a ship and take on the life of a Pirate attacking merchant ships or exploring lost islands. You can play as freedom fighters taking from the rich to give to the poor or as bandits just taking from the rich. You can become a mercenary band of Sellswords wandering the land and selling your skills to the highest bidder.
The campaign's around 2/3 funded with 12 days left to go.