When D&D first introduced the 4e modular "powers" concept, I immediately began thinking how this could be expanded to races. I was never happy with the idea that half-races were limited to half-elves and half-orcs (and with Dark Sun's return, muls). We let people hybridize classes; why not races? Let your imagination be the limit of your racial limits. (Also, this is a nice pressure valve for all the optimizers looking for a good option for rare Ability bonus combos.) Over the years, I've seen plenty of other people ask for the same thing.
On the House Rules & Homebrew forum I've been working on mechanics for introducing hybrid races into 4e. I think they're polished enough for general viewing. Comments are very welcome!Terminology
Parent Race: Regardless of the origin for your character, the two races that you combine are known as your "parent races".
Fixed Ability: Any Ability in which a parent race automatically gains a bonus is called the parent race's "fixed ability".
Flexible Ability: Any Ability in which a parent race may choose a bonus is called the parent race's "flexible ability". Some races have two fixed abilities and no flexible abilities. Humans have neither fixed nor flexible abilities.Flavor
Backstory: A hybrid race has either parents of two races, or his distant lineage has enough of the secondary race and that bloodline just manifests itself unusually strong in this character. (For things like warforged and shardminds, one might even develop a cyborg-style origin).
Limitations: You cannot hybridize half-elves and half-orcs. Actually, if you use hybrid races, you should probably disallow the half-elf and half-orc races and instead require human-elf and human-orc hybrids (unless you deem the half-elf and half-orc to be unique self-contained races).
Appearance: A hybrid race should appear to be a blend of each of the physical qualities of each parent race, with a height and weight that is the average of the two parent races. All combinations must, of course, be approved by the DM. Some combinations, say, a dragonborn-halfling, or a warforged-revenant, may be too bizarre for some campaigns.
Personality: Hybrid races tend to accentuate those personality traits and characteristics that the two parent races share in common, while dulling those personality traits that are contradictory.Mechanics
Abilities: If one parent race is Human, you gain a +2 racial bonus to any two Abilities in which the other parent race can receive a bonus, whether fixed or flexible. If neither parent race is Human, you gain a +2 racial bonus to the fixed Ability bonus from each parent race (your choice, if the parent race has two fixed Ability bonuses). If this results in a bonus to only one Ability (because the parent races each have only one identical fixed Ability bonus), then you get a +2 racial bonus in that Ability and you choose one flexible Ability bonus from either parent race.
For example, a dwarf-elf hybrid must get a +2 bonus in Constitution from his dwarven side and in Dexterity from his elven heritage. An elf-halfling hybrid must take the +2 bonus in Dexterity, and can also choose a +2 bonus in either Intelligence, Wisdom, Constitution, or Charisma. A human-elf hybrid can choose to apply a +2 bonus to two of Dexterity, Intelligence, or Wisdom.
Hybrid Vigor: You gain a +1 racial bonus to all saves, including death saves, and a +2 racial bonus to Endurance checks made to resist the effects of disease. Instead of this racial feature, you may choose one racial feature (but not power) from either parent race.
Keyword: You possess any keywords that either parent race has, such as "undead" or "living construct".
Languages: You speak any languages known by both parent races. If the parent races have no languages in common, then you automatically speak Common. You may also choose one additional language.
Origin: Choose one parent race's Origin.
Power: If neither parent race has the option to gain any racial at-will or encounter powers, you get no racial powers. If one parent race does not have the option to gain a racial at-will or encounter power, choose racial powers as if you were fully of the other parent race. Otherwise, choose either i) one racial at-will or encounter power of one parent race, or ii) one racial power from each parent race, but an at-will power becomes an encounter power, and an encounter power becomes a daily power.
Prerequisites: You are treated as a member of both races for purposes of meeting prerequisites for feats, powers, paragon paths, and the like.
Size: You are Medium in size, unless both parent races are the same Size that is not Medium. (I.e., a gnome-halfling hybrid would be Small in Size.)
Skills: Choose up to two Skills in which either parent race gets a numeric racial bonus, and you receive that bonus. If one parent race is Human, you may forego all racial Skill bonuses and instead choose to automatically train in one skill in which the other parent race gets a numeric racial bonus.
Speed: Your speed is the average of the speeds of the two parent races. If both parent races share another mode of movement in common, you possess that mode of movement at a speed equal to the average of the two parent races for that mode of movement.
Vision: You have normal vision. If both parent races have some other type of vision in common (such as low-light vision) you have that type of vision. Darkvision is considered to include both low-light vision and darkvision for these purposes. If both parent races have a common vision type, but with different ranges, use the smaller range.
Incidentals: You get no other benefits or drawbacks from either race, unless both parent races share the same benefit or drawback. (For example, a drow-eladrin hybrid would get the Trance feature.)Hybrid Racial Feats
You take after one parent more than the other.
Prerequisite: Hybrid Race
Effect: Choose a racial feature (but not a racial power) of one parent race. You have this racial feature. You may take this feat multiple times and choose a different racial feature each time.
You move as well as both of your parent races.
Prerequisite: Hybrid Race
Effect: You possess all the modes of movement possessed by either parent race, and at the highest range that either parent race possesses for that type of movement.
You see as well as both of your parent races.
Prerequisite: Hybrid Race
Effect: You possess all the types of vision possessed by either parent race, and at the highest range that either parent race possesses for that type of vision.