Dragaeran crossbreeds are the product of a birth where the father and mother are from different Dragaeran Houses. Marriage between houses is currently forbidden both by law and custom, but relationships do occur.
Note that the only place that most Dragaeran crossbreeds can find in Dragaeran society is as either Teckla or Jhereg; indeed, House Jhereg—a House created of outcasts from the other Houses—could initially only reproduce by way of unrestrained crossbreeding. (The only known exception to this was Mellar who successfully joined the Dzur, but not many crossbreeds are able to defeat seventeen Dzur Heroes to accomplish this.)
Perhaps by coincidence, but also perhaps because of that House's proclivity for intense passions and lack of foresight, all of the crossbreed individuals featured to date in Vlad's or Paarfi's accounts have been of partial Dzur ancestry: Grita, Mellar, and perhaps Sethra Lavode. Whether due to simple carelessness in regards to birth control, or to a preference for non-Dzur lovers (as seen in Ibronka's romance with Piro, Shant's with Lewchin, or Tazendra's unfulfilled attraction to Aerich), that House seems to generate more crossbreeds, or at least more prominent ones, than most.
Elde Island and Greenaere are not part of the Dragaeran Empire, and appear to have no concept of Houses or House purity. Therefore, the citizens of those places are all crossbreeds of the same Jenoine-modified stock as Dragaerans. Those whom the Dragaeran Empire would consider crossbreeds might therefore be able to go into exile in either of those places, and therefore avoid at least that stigma.
Although most of the novels indicate that crossbreed or halfbreeds are despised by other Dragaerans, references to a change in attitude is apparent in the most recent books. (This has been attributed in part to the breakdown in the normal social structure of Dragaeran society that occurred during the Interregnum).
- See also Speculation:Crossbreeds.