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Aliens & Asteroids
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Aliens & Asteroids

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Saddle up, grunt. There's killin' to be done.

Aliens & Asteroids is a tabletop roleplaying game about gritty, dark, terrifying science fiction stories, combining the uncertainty of space exploration with the horror of discovering beings and technologies beyond our understanding. Set in a futuristic universe where Space Marines do the grunt work for the Dominion, a corporate-led governmental entity that manages all of human-occupied space, you’ll face aliens and horror from beyond the edges of imagination.

You play grunts, sent out into the void to combat aliens, rescue idiots from the fruits of their adventurous spirit, and explore worlds to discover life or technology worth exploiting in the name of humankind. Keep your pulse rifle handy, because there’s a good chance everything you meet wants you dead.

Aliens & Asteroids utilizes the Inverse20 engine, a fast resolution system that utilizes a d20. Included are rules for character and drone creation, setting details, and guidelines for designing missions and alien creatures for your players to encounter, plus a starting scenario that provides a quick start to your campaign!

The rules are focused on allowing you to tell exciting stories around alien encounters, abductions, combats, and horrors, inspired by science-fiction films like Aliens and Starship Troopers, computer games like X-COM: UFO Defense, and television shows like Babylon-5 and The Expanse.

Time to grab a handful of dice, some pencils, some players, and get ready for your next science fiction adventure!


 Customers Who Bought this Title also Purchased
Reviews (2)
Discussions (5)
Customer avatar
neil S November 09, 2019 10:36 am UTC
Does this have alien generators?
Customer avatar
Brian F March 26, 2020 9:19 pm UTC
Wow. Didn't see this message until now! The book includes a number of pre-built alien creatures and rules for creating your own. We have been creating new alien resource guides for the various species mentioned -- the Grey Men and the Skaali are out, with the Gollus and the Dread coming later. So no true random alien generator, but that's a great idea we'll have to ponder for another supplement!
Customer avatar
John G September 06, 2018 1:35 am UTC
Just grabbed this -- looks pretty spiffy, though I'm normally no fan of d20 systems -or- a roll-under mechanic. Have a couple of rules clarification questions -- is there an official forum or G+ group? I didn't see anything on a Google search just now...
Customer avatar
Brian F September 06, 2018 1:55 am UTC
Hi John! We have a pretty active Facebook group for A&A at the moment ( but we haven't had much activity in G+ for quite a while. The other place to look is at the Gallant Knight Games website - would love to get more of a conversation going there. The FB group is where we have the most activity right now, but either works! Or if you want, feel free to just post any questions here!

Thanks for being a fan! --Fitz
Customer avatar
John G September 06, 2018 5:57 am UTC
Thanks for the quick reply, Brian -- will head to the GKG forums, as I'm not a huuuuge fan of posting on FaceBook these days. Nice work on the game.
Customer avatar
Brian F January 10, 2019 5:10 pm UTC
Hey John! Just added the errata as a separate file for download. It includes the rules clarifications we talked about over at the GKG forums -- those are closing, but feel free to pop in here for any questions and we'll get things sorted!
Customer avatar
John G January 12, 2019 8:00 am UTC
Sweet -- thanks for letting me know, and for adding to your already cool game. I still haven't gotten a chance to try it out yet, but it's just a matter of time. Happy New Year!
Customer avatar
Jeremy H March 11, 2018 5:00 am UTC
I'm intrigued but would like to see more of the art and rules before I purchase this one.
Customer avatar
Brian F March 25, 2018 6:56 pm UTC
We added a bit more of the book to the preview and the Quickstart is available here, which has the basics of the rules (PWYW)

Hopefully that gives you a bit of both sides of the equation! Thanks for checking us out!
Customer avatar
Daniel C February 18, 2018 10:17 am UTC
Hey Alan, are we going to see a print on demand version of this book?
Customer avatar
Alan B February 18, 2018 4:51 pm UTC
Hey Daniel! They will be coming! Backers are going to get their copies first, then we'll make sure Print on Demand is turned on for everyone!
Customer avatar
Daniel C February 22, 2018 7:10 am UTC
Thank you Sir! Looking forward to it. If I keep buying your books, I'm gonna have to make a bookshelf space just for your games!!! LOL
Customer avatar
Alan B March 22, 2018 3:22 pm UTC
It's live now Daniel!
Customer avatar
Thomas W February 15, 2018 12:55 am UTC
The download says it should say revised but the file downloaded from the link does not say revised. Is the file linked to the new file?
Customer avatar
Alan B February 15, 2018 1:01 am UTC
Hey Thomas! On the backend it is the revised file, but I had the same issue as you when I tried to download it.

I reupdated it, cleared my cache and it worked! Let me know if that doesn't work.
Customer avatar
Thomas W February 15, 2018 1:11 am UTC
Closed the Browser and signed back in and that cleared it up. The revised file both shows and downloads now.


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Product Information
Electrum seller
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File Size:
7.27 MB
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File Last Updated:
January 09, 2019
This title was added to our catalog on February 14, 2018.