Glorantha can experienced through two roleplaying systems, all developed with, and for, Glorantha.
See here for detailed information on their versions.
RuneQuest Roleplaying in Glorantha
RuneQuest Glorantha uses a variant of Chaosium’s percentile resolution system, Basic Roleplaying (BRP). Other games that use their own version of the system (to name but a few) include Call of Cthulhu, Magic World and Superworld. Six attributes (Strength, Dexterity, Constitution, Size, Intelligence, Power, and Charisma) define a character, along with a culture, occupation and magical association. Skills are percentile, such as Ride (horse) 55% and Spear 45%, with combat resolved using opposed rolls. Armor points subtract from damage rolls, and hit points are mapped to body locations. A blow to the head can kill even the most experienced character – there are no Luck or Hero points to allow rerolls in this game! Along with its own line of products, RuneQuest Glorantha is backwardly compatible with our RuneQuest Classic products.
Have a look at a sample RuneQuest Glorantha character here.
13th Age Glorantha
13th Age Glorantha is a supplement that builds on the Archmage Engine used by 13th Age. As a d20 game its D&D classes and levels will be instantly recognisable, with Gloranthan classes such as Orlanthi Warrior and Earth Priestess also available. 13th Age replaces the D&D skill system with backgrounds, so this book also contains specific Glorathan ones. 13th Age also has a number of unique features, such the Escalation Die used to enhance combat, and One Unique Thing that only that character possesses in the world.
Have a look at a sample 13th Age Glorantha character here.