From the publisher's website:-
Duel is the second expansion to Neuroshima HEX! The box has the same format as the first expansion. It includes two new armies: Smart and Vegas, and a new board as well.
Both armies are well known to all fans of Neuroshima Role Playing Games. Smart is a part of the Moloch army which mutinied and decided to fight against humans as well as against machines. These is an extremely deadly force. Every ally adjacent to Smart’s HQ has the ability to move. It makes this army very flexible and dangerous.
On the other hand there is Vegas, army of men whose weapon is bribery. They can bribe any enemy unit that is adjacent to Vegas’s HQ to make it attack another unit. If your units attack Vegas HQ, you can not be sure when they will stop attacking Vegas and turn to attack you!
In the box there is a new board as well, with new skills on it, special spaces and new rules. It lets players discard tiles or exhaust their Headquater to gain Power points which can be then exchanged into special actions provided by Terminal spaces on the board.