The Grens were a humanoid race dwelling on a planet in an alternate dimension with high technology but no magic. Thousands of years ago they devastated their home world in a vicious civil war. The survivors of that war developed a high level of resistance to radiation and other mutagenic agents; those who failed to develop those characteristics either died out or were killed off by anti-mutant hunters. Eventually the Grens recovered sufficiently from that disaster to send starships out to other worlds, and after colonising several of these worlds they founded a great interstellar Federation. One of their scout ships, the F.S.S. Beagle, crash landed on Mystara in a nation called Blackmoor, with effects that are already well known.
Before anyone could locate the Beagle, however, the Federation collapsed when their androids revolted and eventually took over. One group of refugees from this revolt found their way to the Mystaran solar system and colonised the asteroids that became known as the Pyrithean Archipelago. Several centuries later, the Kingdom of Emerond was founded by a scouting party of Grens from those asteroids.
Meanwhile, the androids who took over the Gren Federation learned the secrets of time travel and interdimensional travel and sought to spread themselves throughout all planes and dimensions. On those worlds where they were found out, they became known as the "Oards".
Gren: Members of this race receive bonuses of +2 to Dex, Int, and Cha and penalties of -2 to Str and Wis. They have NO preferred multiclass. Skin colour ranges from light green to dark green, and hair colour may be green, silver, black, or brown. They receive the same bonus as dwarves to saves vs. poison and magic and gain an additional bonus of +2 to saves vs. the effects of radiation as well as magic whose effects are intended to change a Gren's shape or form. They also gain a bonus of +2 to skills associated with attempts to decipher or use high tech items. Even in dimensions where magic works they are incapable of becoming spellcasters of any type for which an innate talent is required. Thus, they may become clerics, druids, rangers, or monks but not wizards, sorcerers, bards, paladins, or psionicists. They may be of any alignment but are usually Lawful. More primitive Grens such as the Emerondians would lose the bonus for fiddling with high tech equipment but gain a bonus of +2 to hide, or +4 when attempting to do so in woods, assuming that they are not wearing anything that would stand out from the greenery.
Oard: Oards have dark vision (infravision) as dwarves and save as dwarves of 1.5 times their level (rounded down). They are immune to ESP and charm effects and save vs. other mental attacks at +2 over other bonuses. Ability score adjustments and limits are set as follows:
Str: No adjustment (minimum 8)
Dex: No adjustment
Con: +2 (minimum 8)
Int: +4
Wis: -4 (minimum 6)
Cha: -2 (minimum 4)
They have NO preferred multiclass. Skin and hair colour are as for Grens. They gain a bonus of +4 to skills associated with attempts to decipher or use high tech items. Even in dimensions where magic works they are incapable of becoming spellcasters of any type whatsoever -- they are limited to mundane, non-spellcasting classes. They cannot be Chaotic and are usually Lawful.
Karimari: The Karimari are descended from matings between the Grens and
Tanagoro humans. They have -2 to Str, +2 to Int, and may be members of any class
other than the Mage class. They are shorter than both of their parent races.
They take after the Tanagoro in terms of colouring and after the Emerondian
Grens in terms of philosophy.