Dice
The Contract uses Fudge dice (also known as Fate dice). Ideally, each player should have a set of four Fudge dice, though of course it's possible to share.
Fudge/Fate dice can be purchased many places on the Internet. The most important consideration in selecting dice is legibility. When you roll your dice, everyone at the table should be able to read them easily at a glance. One option is to purchase a GM Pack, which includes five sets of dice, from Grey Ghost Press. Alternately, you could purchase a Players Pack of a single set of dice from the same site. Grey Ghost's GM Packs and Players Packs have good contrast and are easy to read.
Recommended Reading
Reading the following comic books may be useful in learning the feel of The Contract. The original comic books or graphic novels are strongly recommended instead of TV or movie versions or later adaptations.
Recommended Viewing
The following could be considered to be in the same "genre" as The Contract. Some are better than others.
In addition, series such as The Hunger Games, Battle Royale, and Animal World could be considered loosely related (to Highlander Contracts if not to Contracts in general).