Generally, the cards were distributed in Promotional Cards or Sets, sold in Series Boxes of foil packs (intended for individual retail sale), and sold in an end-of-year Factory Set. In 1991 and 1992, the Factory Set included all cards from the year; in 1993 the Factory Set did not include every card available.
The Factory Set cards had silver borders. The Series Box releases featured other border colors (generally gold, though very rare ruby cards could be found). The Promotional cards had different border colors depending on the exact distribution.
It is possible to collect two different sets of the cards - one set with gold borders (from foil packs) and one set with silver borders (from Factory Sets). In theory, a ruby bordered set could be assembled as well.
Seventeen cards from the 1991 set and seventeen cards from the 1993 set were published in Dragon (Issue 160 - Aug 1990) and Dragon (Issue 180 - Apr 1992), respectively. These cards also were republished in their respective annual Factory sets.