GameScience was one of the very first RPG dice manufacturing companies way back at the birth of the industry when Dungeons & Dragons was first created. GameScience dice are also known as precision dice, and are specifically manufactured to ensure that each side of the die is the same size as the other sides, in an effort to ensure that the dice roll true. This is precision dice effect is achieved by avoiding any sanding or polishing processes (which cause the rounding on the edges of normal RPG dice).
As a result GameScience precision dice have their signature sharp edges. There are, however, two negative side effects: first, GameScience dice are manufactured un-inked. If you want the numbers filled in, they have to be inked by hand with a permanent marker. The second negative side-effect of skipping the sanding process is that there is a noticable sprue, or chunk of plastic sticking out where the GameScience dice were removed from the mold. GameScience claims that this does not affect the ability of the precision dice to roll true, but you can remove it by carefully sanding it down with sandpaper.
GameScience claims that their dice roll more true than other gaming dice. We put the claim to the test in a 10,000 roll test. Our results showed that the sprue on GameScience dice had a major impact on rolling 7 and 14, but other than that the dice did roll more true than Chessex dice; however, neither dice rolled truly randomly, and both rolled close enough for gaming purposes: you'd have to roll thousands of times before you saw the difference in the Chessex dice. In our opinion, you should buy GameScience precision dice because you like their look. The improvement in randomness is mostly solving a problem that doesn't seem to really exist.