The new Spelljammer: Adventures in Space set for six new playable Spelljammer races to D&D. These races technically debuted as playtest material in an Unearthed Arcana article called "Travelers of the Multiverse," which was the first hint that Spelljammer was returning to D&D. The six races are now in the Astral Adventurer's Guide and all of them have been changed to some degree in their official debut.
The six Spelljammer races are the astral elves, autognomes, hadozee, giff, plasmoids, and thri-kreen. The astral elves are the most familiar of the bunch, as they are elves who left the Feywild and ventured out into wildspace, with their bodies being altered by their exposure to the Astral Plane. The autognomes are a race of artificial gnomes that were created by the gnomes of Krynn from D&D's Dragonlance campaign setting, the hadozee are humanoid monkeys that can glide and climb riggings with ease, the giff are humanoid hippos that excel in both melee combat and using firearms in battle, the plasmoids are oozes with the ability to reshape their body to their needs, and the thri-kreen are insect creatures that are more commonly associated with the Dark Sun campaign setting, but they now appear in Spelljammer with multiple arms and natural telepathic abilities.
These intergalactic races are an important part of the flavor of Spelljammer. This is a setting where players will ride on magical spaceships and sail the stars, so it makes sense for their to be some unusual playable races in wildspace, as players are dealing with aliens and magic machines. The reason that the Spelljammer Unearthed Arcana article was released in the first place was to see how they functioned in live games, ahead of the launch of Spelljammer: Adventures in Space. Wizards of the Coast received all the player and used it to retool the Spelljammer races and make sure that they're as balanced and as fun to play as they can be.
The D&D Spelljammer Races That Had Major Changes Since Unearthed Arcana
Not all the Spelljammer races from Unearthed Arcana underwent major changes in the Astral Adventurer's Guide. The only change to the autognome in the Astral Adventurer's Guide is that True Life is now called Healing Machine, and it specifies that they benefit from D&D's mass cure wounds and mass healing word spells, which wasn't specified in Unearthed Arcana. This change to autognomes is just a clarification of an obvious point, as it stands that they would benefit from the mass version of the spells that normally benefit them, but Wizards of the Coast made sure to codify it in the book.
The plasmoids in the Astral Adventurer's Guide now must use an action to create a body with Shape Self. Unearthed Arcana stated that this was something that can be done without using any actions, which is rare in D&D 5e, but the pseudopod ability of the same feature can now perform actions as part of the same bonus action used to create it from the plasmoid's body, allowing the plasmoid to be able to influence objects with their new limb in the same round that they formed it. The thri-kreen in the D&D Astral Adventurer's Guide have a more defined list of actions they can use with the Secondary Arms feature (though the part that claims they cannot use shields with the arms has been taken out), the Sleepless Revitalization feature is now called Sleepless, and Thri-Kreen Telepathy clarifies that the thri-kreen cannot communicate through conventional means.
In the Astral Adventurer's Guide, astral elves have combined their Trance and Trance Proficiencies features from Unearthed Arcana into a new feature called Astral Trance, and instead of getting a weapon and tool proficiency after a long rest, they gain a skill proficiency and either a weapon or tool proficiency as the second choice, making it a lot better. Astral elves have lost the Radiant Soul feature, which healed them on a successful death save, making them very difficult to kill. Radiant Soul has been replaced by Starlight Step, which allows them to teleport up to 30ft away as a bonus action, which can be used a number of times equal to proficiency bonus and replenishes on a long rest. It's likely that Radiant Soul was scrapped for balance reasons, as it meant that an astral elf only ever needed to one death save to escape from final death, which byes one of the D&D combat system's most important mechanics.
The giff in the Astral Adventurer's Guide have lost access to the Damage Dealer feature, but they have gained two new ones in its place: Astral Spark and Firearms Mastery. Astral Spark lets the giff deal their proficiency bonus in force damage during an attack, which can be used a number of times equal to proficiency bonus and replenishes on a long rest, while Firearms Mastery grants proficiency in firearms, lets the giff ignore the Loading property of firearms, and lets them fire at long ranges without gaining disadvantage.
The hadozee in the Astral Adventurer's Guide can no longer use Dexterous Feet to perform the Use an Object action as a bonus action. Instead, they have a much smaller list of actions they can perform with their feet, such as being able to interact with Tiny-sized objects, which is considerably worse than before, as it means the hadozee have lost the ability to use some special D&D Fast Hand rogue tricks with their feet. It isn't all bad for the hadozee in the Astral Adventurer's Guide, as the hadozee now have Hadozee Resilience, allowing them to roll 1d6 + proficiency bonus as a reaction when taking a hit, in order to reduce the damage. Hadozee Resilience can be used a number of times equal to proficiency bonus per long rest. All the changes in the Astral Adventurer's Guide have been mostly positive ones, as even the removed abilities have been replaced with better ones, and the additions have made these Dungeons & Dragons races better than they were before.
