Net Epic consists of a generic rule system, and then another rule-system for each race. There are races such as the Space Marines, the Orks, and the Tyranids. Each race needs to have playing pieces to go along with them.
Rules can be found here: http://www.netepic.org/netepic.html
There are two different sets of rules. The color one, "netepicgoldcorerules.pdf", takes a ton of ink to print. And since it is going to be the first book you send your inmate (and you may not be sure it will make it in), you may want to print the simple/clean version of the rules "01_netepic_core_rules_v5_final.pdf" mentioned later on down the page.
You need to download the army list for the various races (farther down the document). Each of the armies begin with a number, though the 04 set is a bit mixed up. For the Space Marines, you want the 04b_adeptus_astartes_army_book_v5_final.pdf and probably 04a_adeptus_mechanicus_army_book_v5_final.pdf books. But the 04c_adeptus_militaris_army_book_v5_final.pdf file belongs to the "Imperial Guard." Other than that, the rest of them mostly come one number per race.
The main thing I needed to get it to work, was to make paper chits (playing pieces). Normally, net-epic is played with metal playing pieces that people spend a lot of time buying, painting, and gazing at with great adoration. Two-thirds of the game seems to be in preparing their army to do battle. But in the prison system, you cannot have these pieces. I spent a fair bit of time scouring the Internet for pictures of the playing pieces and turning them into paper versions. Most of the pieces are not documented how large they are, so I have had to guess for some of them. But my paper chits are below. I did my best to only use images that were in the public domain, and because they are as drastically changed (shrunk, had other images added along-side them, etc) I do not think there are any issues with them being used in this way. But my race files are at the end of this page.