Board Games are Totally Math! : Star Realms

Welcome to a long overdue edition of Board Games are Totally Math! Today I want to look at the numbers behind Star Realms., a two-player deck builder about building up your fleet of space stations and ships until you are strong enough to wipe out your opponent before they do the same to you. Currently sitting at a handsome 70th in the BGG board game list, this tiny box is a good contender for best ratio of quality design to expense.

So let’s head to the engineering section, and see how numbers power these beautiful star ships.


Fleet Building

Star Realms is undoubtedly a deck builder. You start with a weak deck, drawing trade ships and basic fighters. By the end you are throwing down huge warships and planet sized bases. It’s a great feeling, building your forces to that point, and is the practical definition of deck or pool building. But what is going on mathematically when we build a deck. Well quite simply, it is odds manipulation.

When you start a game, you have zero chance of doing any considerable damage, the most you can hope for combat wise is to draw two vipers for two damage. As you build your deck, you stack the odds in your favour to draw out more useful cards on any given turn. You could stack the deck with high damage cards, or carefully buy cards from a faction or with certain properties so that you have the best chance of pulling off devastating chains or combos.

I recently introduced a friend to Star Realms as he had had a bad experience with his first deck builder play through. His game club had asked him to play the Resident Evil deck builder and from the sounds of it, did a bad job of explaining how the concept of deck building worked. He asked them “Why do I have to get rid of my bullets, aren’t bullets useful?” and his teachers responded “You just do.”

A better response would be to say that you are stacking the odds in your favour. When you can only draw five cards on your turn like in Star Realms, every Scout or Viper is a waste of space that could potentially be filled by something far better. Literally anything in the Star Realms deck is better to draw than the starting cards. So building your deck comes down to adding strong ships, weeding out the weak, and planning what you add so that they work best together.

Warring Factions in the stars. One might call it star… wars

One of the fun elements of the building of your deck is the factions. I have known people perfectly well buying ships from any old faction, but the factions are each tailored to differing strengths and weaknesses, thereby helping you to easily steer your deck towards attributes that match your tactics or play style. I think looking at the factions and their individual cards is going to yield the most interesting statistical analysis. But before we get to that, I want to indulge try something else. From a number of plays before I started looking at averages, I formed opinions on the factions from how it felt to use them.

This is, as unbiased by hindsight as I can manage. My pre-statistical thoughts on the factions. How will they compare to my conclusions after looking at the numbers.

  • Blob

A blunt implement. I got the impression that the Blob were intended to be an all-out attacking force, few special powers, lots of ally bonus combat, simply a swarm of attacking mindless creatures. In some ways the theming of this faction is just right, a very alien race that attacks in force and in numbers

  • Trade Federation

Well it’s right there in the name. They are good at trade. I felt like they were good for spending power, healing damage and offering good defence from their bases. Maybe a good starting faction so you can spend big on ships, but weak in combat for the end game. Most of their combat seems to come from scrapping cards.

  • Machine Cult

Great for scrapping cards. Good combat strength and some useful unusual powers. I felt like these cards were ones to pick the odd few from, just to be able to scrap the weaker cards, but with some good combat uses

  • Star Empire

Close to Blob for cheapest faction. Not very high powered in combat, but with a lot of ability to draw extra cards making it a great faction for pulling off big chains.

So how did I do?

I will put up my spreadsheet of the factions with averages and totals of all kinds of things. You can find it here.

What do the stats say about the factions, how close was I in my initial thoughts?



With cards having an average base combat value of 3.55 and a total of 71 combat across the faction, plus an extra 0.7 combat on average per card if there is an ally present. The Blob blows the other factions out of the water in terms of raw attack power. In cost, they are the cheapest overall in terms of average expense per card. They have the most 1 and 2 cost cards of all factions. The stats back up the idea of them being a swarming, horde or a faction. They have 8 cards that offer draw card abilities, but 6 of them require an ally. But in fact their combat from ally powers is actually the joint lowest with two other factions, with Star Empire having the most ally combat. Although they certainly do work together better than any other faction. Only 4 Blob cards have no ally power, lower than the others with 7 or 6.

One thing I did not pick up on is that their scrap abilities tend to favour trade, which, with their low cost, suggests to me that the Blob is intended as an early faction to be scrapped in favour of others later on since scrapping cards for trade would be less useful in the end game.

Trade Federation

Well no surprise the Trade Federation are good for making money. A total of 31 trade is on offer from the blue faction, meaning you may be fighting over them if you want to afford the big ships. As for healing (increasing authority) they aren’t just good. They are the only option available. Without Trade Fed ships, your authority can only go down.

I said it felt like they have good defensive bases. Which I am not so sure of, it is a balance really. They are far better than the blob with the lowest shield total and no outposts. Yet in terms of blocking power, the machine cult and Star Empire have a little more total shield strength than the Trade Feds and the two have only out outpost between them, meaning opposition cannot bypass the bases to deal direct damage. The Trade Feds have 4 outposts of the 7 bases on offer. Perhaps what makes the Trade Fed bases feel so good in defence is their heal abilities.

I think it is somewhat inaccurate to say most of their combat comes from scrapping. In reality, scrapping accounts for about a third of their available combat. With the right ships, there is some damage to be done, but in reality, they do not look like a strong endgame faction.

Machine Cult

Sure these guys are the scrap faction. In fact apart from two blob ships, there is nowhere else to go to scrap you cards. If you want to lose those weak starting cards, better get some reds. I felt like they had the most unusual powers, but really they have the least cards with unique powers. Only the stealth needle and mech world had powers I couldn’t otherwise fit onto my chart. And though they have the second lowest combat potential. There is some decent strength there, which in combination with their other abilities, makes the Machine Cult worth considering for the attack minded player.

Star Empire

I feel like I was way off here. Although they do have a number of cheap ships. They are not far off the average cost per ship, and in truth, they have the fewest 1 and 2 cost ships. Saying they were fairly weak Is inaccurate, in fact they have the second highest combat total, and this, paired with the abundance of draw card abilities, means they can be a formidable force in combat terms. The average base combat across all purchase cards is about 2.2. This means that effectively, whatever is in your deck, you can think of a draw 1 card ability on a ship as being worth 2.2 extra combat over time, in addition to any other benefits the drawn card might end up having. A strong ability, and why Star Empire are probably my favourite faction.

Another thing I didn’t mention is the ability to make your opponent discard a card. Only the Star Empire has this ability, and with enough of them in your deck, you can pretty much have your opponent playing with a permanent handicap of only drawing 4 cards per turn.

So there we go. Just a short one for Star Realms. As you can see from the length of time since the last article, I am struggling for time to make these. That and Star Realms didn’t turn out to have much in the way of statistically measureable gameplay. So much of the powers on these cards does not translate into number form very well.

But still, we can see from the spreadsheet some of the intention in the faction system. On the one hand, you want a bunch of the same faction in your deck to make the most use of the faction powers, but on the other, you cannot get all you need from one faction. I would suggest a balanced diet. Something like a food pyramid. With the factions that match your chosen tactic at the base, and a few cards from the others to get the abilities you need that your main factions cannot provide.

Trying to pin down the probabilities on a game that by definition has you, the player, manipulating and changing the odds constantly was perhaps an ambitious task. I thought about plotting a cost to power output graph as a whole and for each faction to see which cards but I think any value I placed on the differing powers would be arbitrary and not very informative. Then there is the fact that the currency in this game is somewhat volatile. There is no saving up for something better. You simply spend all the money you have available on that turn or you lose it. You can buy the explorers as a kind of savings plan but they are not a reliable way to save and you may never get the money back you put into them.

As always. Thanks for reading. I am working to do better so by all means let me know if something needs improving. I don’t feel this was as great as the previous articles I wrote, perhaps I should chose my subject better next time. On that note, any suggestions for games I should are appreciated. Next I might take a look at Pandemic the Cure. I have been playing this a ton recently and the probability of the dice rolls is key to how the game plays and how balanced it is. Click subscribe for a good chance of seeing Pandemic the Cure broken down, tabulated and analysed, and hopefully other games too at a much accelerated rate.


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