In 1996, Chaosium decided to join the ongoing collectible card game boom and published Mythos, designed by Charlie Krank.

[2] Later expansions however, most notably the non-collectible Standard Game Set, fared poorly and forced Chaosium to discontinue Mythos.

[3] Editor Scott Haring said "Mythos was a very deserving game, with great art and gameplay that involved more than just monsters fighting each other.

"[3] Mythos was designed to include a high level of player interaction, in the vein of some traditional card games like rummy.

Increasing the number of players makes completing adventures more important, and encourages development of other strategies other than disrupting an opponent's game.

When a player reaches the number of adventure points previously agreed upon (usually 20), the game ends after the current round and the winner is determined.

Allies (as well as all other card types) are used to satisfy different Adventure requirements and know languages that make comprehending foreign Tomes possible.

The allies featured in the set are drawn mainly from Lovecraftian fiction, but also include real-life people, mostly authors, as game characters.

Events represent calamities, phobias, weather conditions, day-night cycle, methods of travel, and other surprising things that can happen to one or more investigators or cards.

During the game, investigators travel to different locations by walking or by using different methods of transportation (by playing Event cards such as Train).

Examples: Massachusetts State Hospital, R'lyeh Playing a Monster requires certain locations which are marked as a "gate", and can usually only be used once.

Mythos was available in boosters and starters, which contained a fixed number of common, uncommon and rare cards distributed randomly.

[8] Mythos Limited Edition was distributed in Starter decks and in the three booster pack expansions (Expeditions of Miskatonic University/Cthulhu Rising/Legends of the Necronomicon).

[13] New Aeon (1997), at times known as Mythos Now before its release,[14] was a 200-card stand-alone expansion set distributed in the same way as The Dreamlands.

"[17] Paul Pettengale reviewed the Cthulhu Rising expansion set for Arcane magazine, rating it a 6 out of 10 overall.

"[19] Allan Varney, in a review published in The Duelist, stated that the rulebook supplied with the original set is "opaquely written and requires study", but that the rules "are rather simple".