So you want to run A Kingdom Of Stars And Shadows. Here is how you actually do it.
I picked up the core rulebook about three years ago because someone in a Discord server I was lurking in kept posting screenshots of the homebrew settings. The system itself is a low-magic d20 variant with a built-in tension mechanic called the Starfall Track. Most people get through the first chapter and then hit a wall when they try to run a second session. That is not the system's fault, but it is not immediately obvious why that happens either. The basic loop is simple. You describe the scene, the GM draws from the Starfall deck (a set of 52 cards you buy separately or can print), and the players roll against a modified d20 that factors in three separate modifiers: your alignment angle, your shadow debt, and the ambient starlight rating for whatever zone you are in. That last one is where most new groups mess up. I ran a campaign in a dense forest zone for about four sessions before I realized the players were treating the ambient starlight as a static number. It changes every time the moon phase shifts in the calendar, and the rulebook mentions this in a footnote on page 47. I had been recalculating it manually until my friend pointed out that the companion app called Astrolabe does this automatically. Takes about two seconds now instead of ten minutes per session.
The shadow debt mechanic is the part that actually makes this system different from anything else in the same price range. Every time your character makes a selfish choice or abandons an ally, you add a shadow token to their debt track. At three tokens, you gain the Withered condition which imposes disadvantage on all social rolls for the rest of the scene. At six tokens, the GM is supposed to introduce a literal shadow entity that haunts the character until they perform a genuine act of redemption. Most groups skip the redemption requirement and just keep playing around it. The rules do not actually support that. I found out the hard way when my players hit six tokens and I told them nothing happened because I was lazy about tracking it. The next session one of them rolled a natural 1 on a persuasion check and the system was supposed to escalate to a full haunting event, but because I never applied the condition properly the whole thing just fizzled out. I had to retroactively apply a modified haunting to that character using the optional rules on page 198 and it took me about twenty minutes to sort through the math. If you are looking for where to get the materials, the core rulebook is available from most major RPG retailers. The Starfall deck is sold separately and costs about twenty-five dollars if you go the official route. There are third-party decks on places like DriveThruRPG for about twelve dollars that work fine. The rules are not locked to any specific card brand. Just make sure the deck you use has the proper symbol markings on the back so players cannot see through them during play. I learned that one the hard way too. The biggest counter-intuitive thing about this system is that more shadow debt is not always worse for your character. The rules explicitly allow a six-debt character to access the Eclipse Path subclass at level 5 instead of level 3. A lot of GMs do not read that part and accidentally nerf players who lean into the dark choices. If you are running a group that likes morally gray characters, you should point this out at character creation so they know they are not just handicapping themselves.
On the other hand, the system breaks down completely if you try to run a high-magic campaign with it. The Starfall Track was designed for a world where magic is rare and dangerous. If your players start casting third-level spells in the first session, the whole tension model collapses and you end up with a broken damage curve. There is no workaround other than adjusting the spell power scaling manually, which the author acknowledged in a blog post from 2023 but never officially patched into the rules. If you need high magic, look at something like Realms of Arcanum or just use a different system entirely. Another thing nobody really talks about is the encounter balancing table on page 134. It assumes a party of four at roughly equal levels. If your group has three players or five players, you have to adjust the encounter XP values by 20 percent for each player above or below four. I did not catch this until my three-person group walked into a fight that should have been deadlier. One of my players nearly died to a encounter that was supposed to be easy. After that I started running the balancing math before every session and it takes me about five minutes now. The first few sessions were rougher than I would have liked. The rulebook itself is about 220 pages and written in a fairly dense style. It is not beginner-friendly in the way that some modern systems are. If you have never run a tabletop RPG before, plan on spending a full weekend reading it before you ever pull up the character sheets. That said, once you understand the framework, the actual runtime is quite fast. A typical session runs about three hours with minimal downtime between rounds.
Get the Full Details
If you want the PDF version, the official publisher lists it on their storefront along with individual product listings for the card decks and the character sheet packs. There is no single download bundle that includes everything and trying to assemble your own kit from separate files is where a lot of people waste their first week with this system. Just order the starter bundle if you are new to it. It includes the rulebook, the card deck, and a set of pre-generated characters that cover most of the common archetypes. That alone saves you probably four to five hours of setup time compared to building everything from scratch.
