The Game Beyond (Melissa Scott)

Once upon a time, the space empress died. But don't worry, she left a very clear will leaving the empire to her favourite. Even his enemies have to agree the will is unambiguous and foolproof. Her intent, the letter of the law, and imperial Convention (always capitalized) mean that Keira gets to be the new emperor.

But, just in case, he shows great magnanimity and extends an offer to any other aristocrats to challenge him for the throne. Now, in the space empire, everyone takes noblesse oblige very seriously; we can't have ordinary war, because in war, commoners die, and that's very bad. So several aristocrats challenge him to various video game simulations. He wins all of them. It helps that he has Talent (also a proper noun), which in this case means "being sometimes able to see into the future and psychically find patterns because all the nobles are weird and inbred like that."

Most of the defeated enemies swear loyalty to him, as per Convention. But Eduoard doesn't and decides to fight a war about it. After consulting with his sister, a space Catholic nun, he starts a small-scale war. Again, Keira uses his Talent and defeats the pretender.

This is like...Dune fanfic by someone who doesn't care about Arrakis. Like, what if space monarchy and space inbred nobles and space psychic nuns? Okay, and?

In Ender's Game, even just the Battle School sequences, we have a sense of the rules of the game. We see enough "normal" (ish) battles to understand the different strategies, and when Ender exploits the loophole with "the enemy's gate is down," it means something. Here, all the video game fights are standalone chapters, and any interesting practice or strategy is just fast-forwarded through offscreen. Keira uses his Talent, he sees a winning strategy, he wins, repeat 4x. ("Guy has to win video games to become space emperor" was the Yuletide promo, but that's overselling it imo.)

There's also a subplot about "was this all set up centuries in the past so my ancestor could win a bet with the ambassador's ancestor?" Involving magically inherited memories that Keira has access through (because of his Talent, of course). Again, the less-interesting (to me) parts of Dune, with a hint of the Mists of Avalon reincarnation nonsense. Towards the end this turns into themes of "why do we even have an empire anyway, isn't this system going to break down eventually," which could be interesting as its own take on the trope (and the cycles of decadence/decline is also a thing in Dune), which sort of makes the end unique, but it's too little, too late.

Eduoard's home planet has a fun holiday for the first snowfall of the year, that worldbuilding was unique and cool. I wanted to see more about what space Catholics actually believe and practice--there's a description of Eduoard's triptych featuring the "Donna" (Virgin Mary) and St. Michael, the warrior angel, which was neat. But again, not enough of this.

Keira comes from a noble house that used to be a big deal before they got demoted. Their name is the Renaults. I think this is the author having fun and indulging her own id, because there's a novelist named Renault who wrote a bunch about the Greek empire.

In Dune, we have planets like Arrakis, Salusa Secundus, and Caladan. Even if a lot of the glossary terms are thinly-disguised space Arabic, there was at least an attempt made to have original-ish proper names. In The Game Beyond, the space settings have names like Castille, Sahara, Babylon, Hell, and Somewhere Else. Hell is at least described as painfully hot (they sleep during the day and go out at night), but there's no real description of these places. It's just..."instead of filing off the serial numbers I'm just going to indulge my own id with imperial extravagance, but in space." Respect the hustle, it just wasn't for me.