In terms of primary sources, all our knowledge of Eostre comes from a single text: Bede’s eighth-century treatise on the Christian Calendar, De Temporum Ratione (On the Reckoning of Time). In Chapter 15, “The English Months”, Bede writes:

Hrethmonath [March] is named for their goddess Hretha, to whom they sacrificed at this time. Eosturmonath [April] has a name which is now translated ‘Paschal month’, and which was once called after a goddess of theirs named Eostre, in whose honour feasts were celebrated in that month. Now they designate the Paschal season by her name, calling the joys of the new rite by the time-honoured name of the old observance

It’s not much to go on. It’s a tantalizing allusion that does not reveal much --if anything—about who Eostre might have been or what role she may have played in Anglo-Saxon heathenry. Of course, that has not stopped scholars from debating the passage and that debate is worth referencing here along with some general observations pertaining to our ability to reconstruct ‘pagan’ practices from later, Christian sources.

To be blunt: there is no scholarly consensus on the existence of Eostre as a goddess in the Anglo-Saxon pantheon. Audrey Meaney (1985) argues that Bede’s month-names are related to season-specific rituals and that Bede’s mention of obscure goddesses, precisely because they are unexpected, is indicative of their authenticity. Gale Owen (1981), notes the etymological connection between Eostre and other Indo-Europeans ‘dawn goddesses’-- the Vedic Usas, Greek Eos, and Roman Aurora. The PIE root for all four is *aus- “to shine”, usually in reference to dawn. On the other hand, other groups of scholars have questioned Bede’s accuracy when depicting Anglo-Saxon pagan practices a century after conversion (Wood 2000). Ray Page (1995) accuses Bede of dabbling in etymological speculation to explain the name of the month. Dubious etymologies are not uncommon in early medieval Europe (see Isidore’s Etymologiae) and Page argues that the name instead has its origins in Easter dawn vigils-- again, the root of the word being ‘dawn, east’.

Broader criticisms of Bede have their root in our ability to glean authentically pagan elements from medieval Christian sources. And to that point, medieval ecclesiastics don’t have the best track record as ethnographers of non-Christian religious practices. In other words: even if we accept that Bede is broadly correct identifying Eostre as a goddess within the Anglo-Saxon pantheon, we should be wary of attempts to reconstruct pagan practice or take medieval authors’ descriptions of such at face value. Descriptions of pagan practices are frequently embedded in polemics that decry improper belief and practice, often relying on literary tropes that situate the ostensibly pagan practices within a paradigm that divides the world into ‘not-Christian’ and ‘Christian’ spheres. The current trend in scholarship leans towards skepticism, that we are unable to distinguish authentic pagan elements from the Christian texts that describe them. In a lot of respects, this is a consequence of the postmodern turn that emphasizes the “finality of the text” (Cusack 2007) as well as a response to earlier historical scholarship that played fast and loose with reconstructions of pre-Christian religion.

So the dissatisfying answer is that an Anglo-Saxon goddess named Eostre associated with the dawn and April festivals might have existed, and that her name might have given rise to both the month and the English translation of the name for the Christian holiday. What those earlier celebrations might have looked like are beyond our ability to reconstruct without a very large dose of speculation and imagination.

The good news though is that DND is an exercise in the imagination (you probably don’t need me to tell you that!). So historical accuracy isn’t the end all, be all. A dawn goddess that sends a plague of egg-hatched hares in a springtime ritual gone horribly wrong sounds like the premise of a great one-shot campaign and one I'd like to play.