Philosophy of Tabletop Game Design: Engine Building



We’ve seen some popular mechanics showcased in the role of action selection but many are also found in ‘engine building.’ A motor race is won not just by making good turns but by having developed a good engine to drive with. By ‘engines’ in board games we mean processes players work through to pursue their goals, which is perhaps more comparable with how a business or economy develops. For example, the resource management game Splendor is about more than just collecting jewels to purchase cards worth victory points, it’s also about knowing when to spend your turn (and jewels) on cards that increase your income of certain jewels, hence allowing you gain more points in the long run. This investment of time and resources to develop your abilities is ‘engine building’. It is using your present turns in a way that improves your ongoing economy and hence the effectiveness of your future turns at achieving your ultimate goal.


Perhaps the most basic mechanic for engine building is unlocking upgrades to your abilities. For example in Chess you can upgrade a pawn into a Queen by moving it to the far end of the board. We certainly wouldn’t call Chess an ‘engine building game’ because the possibility of doing that is so restricted and rare. But in games like Copenhagen and King of Tokyo players can unlock various new abilities throughout the game. Sometimes these abilities can then be used repeatedly, others are more restricted, but upgrades are an excellent way of introducing engine building into a design because there is pretty much no limit to the different ways they can be gained or what abilities they could grant. Upgrades that give you more actions or action points are particularly desirable as they directly allow you to do more. We see this in worker placement games where you can recruit more workers, but this often comes at the cost of paying a recurring wage of to them.

As with worker placement, engine building also often goes hand in hand with resource management, and as I said of Splendor above, increases to your income are a great type of upgrade. Indeed, increasing your ongoing income levels is a core feature of the phenomenally successful sci-fi game Terraforming Mars. But pretty much any economic game will feature engine building because as your resources and profits grow you are able to buy and sell more than you were before, thereby increasing the effectiveness of your turns.

Tableau Building

The civilisation themed 7 Wonders is an example of a resource management game that uses tableau building rather than worker placement. This mechanic is where each player builds up a static display of cards/tiles in their play area. This can be engine building if the abilities or actions you have access to grow along with your display. In the case of 7 Wonders these only increase your income or decrease other costs, but that’s part of what makes what is otherwise a strategically deep game so simple to play, a formula that has won it dozens of awards.


The world’s Wonders have always been sources of superstition

Of course, having cards played in front of you that aren’t discarded at the end of turn is a basic concept, and tableau games don’t necessarily involve building an engine, but building scoring opportunities by playing combinations together. This is expertly distilled to its essence by Sushi Go, a party game that is almost as popular as 7 Wonders. This combo play also works excellently in Among the Stars, a game that has a small amount of resource management making it sit neatly between the aforementioned two games in complexity level, and is distinctive because the positions in which you place your cards matters. Thereby adding a bit of the geometric aspect that makes tile-placement games like Patchwork so popular.


Among the Stars also has a new app version

In games focused on collecting a good combination of cards the mechanic through which you receive cards is particularly important. And another thing that makes these three tableau building games work well is that they all use the card drafting mechanic where the hands of cards don’t belong to a particular player, but each player picks one card and passes the remainder of the hand on. The hands cycle between the players, and because they pick simultaneously it streamlines these games, and they remain fun with larger numbers of players. As with blocking in action drafting, you can frustrate your opponents’ plans in card drafting by taking the cards they’d want before that hand is passed round to them- a move commonly known as ‘hate drafting’. Of course, there is cost to hurting someone else if another card would be more positively useful to you than the one you take to deny another player. But Games like 7 Wonders promote hate drafting as an option by having always available actions that allow cards you don’t want to keep to be used for other things. For example, when you pick a card to use for building a stage of your wonder instead of playing the card.

Deck Building

Like tableau building, card drafting is not in itself a form of engine building, but there’s a type of cardplay that certainly is: deckbuilding. (Yes, a lot of these mechanics are labelled as ‘building’!) Whereas card drafting subverts conventions by making the players share the hands of cards by passing them between each other, deckbuilding subverts conventions in the opposite direction by giving each player a personal deck to draw from, rather than them all drawing from a single shared deck. Players then build their engine by improving their own deck over the course of the game, thereby improving the cards they draw and play with. Note how this contrasts with games like Magic: The Gathering for which you can construct your own deck to play the game with, because you are not building your deck before the game, but within it.


Popular deckbuilder The Quest for El Dorado has just been reprinted in a 2nd edition

In deckbuilding games typically you have to draw all the cards in your deck before it’s reshuffled again and the new cards you have acquired can start to be drawn. While your deck may be refined by adding cards that grant new or more efficient effects, any card you add dilutes the deck by making it less frequent for any one card to cycle around into your hand. This cost to gaining cards really adds up if you’re adding cards every turn which are mostly ok rather than great, so it is also important to refine your deck by removing worse cards from it.

Different games have different, harder or easier, ways you can purge your less useful cards like the cards each player starts with in their deck. In Ascension, like all of these games, you have cards which give currency for buying new cards (including cards that improve your future income) but to to purge cards in this game you have to buy cards that have that effect. And these can be hard to come by. Whereas in Arctic Scavengers you can always simply purge as many cards from your hand as you want, which in keeping with its bleak post-apocalyptic theme, often amounts to driving out the refugees you start with into the wasteland of the scrapheap. However in both these games, most of the cards are worth at least some victory points so it is not a total waste if at game end not all your cards are an essential part of your engine.


My friends playing Flamme Rouge (with expansion) in London’s South Bank Centre

Most deckbuilding games are card games based on accumulating victory points and/or attack points to defeat an enemy, but the mechanic works equally well in other game styles. Slay the Spire is critically acclaimed video game in which, despite not being based on a tabletop game, the action is driven by deckbuilding and acquiring cards from defeated enemies. The Clank! series are board games in which you build your engine through deckbuilding, allowing you to better move across the board to grab treasure and get back before your opponents. The Dice Masters game system adds engine building to a Magic: The Gathering style head-to-head fight, where you use deckbuilding mechanics to build the pool of dice you draw from rather than a deck of cards. Dice Settlers and Manhattan Project: Energy Empire are great complex board games that use similar dice mechanics. But the comparatively family-friendly Dice Forge takes this to the next level, as throughout it you are improving the sides of dice you roll to drive the game, literally building the dice themselves rather than a pool of dice.

A major variation between deckbuilding games is how the market from which you buy new cards is structured. In the game that debuted the mechanic, Dominion, the same 10 cards are available for all players to buy throughout game, at least until all the copies of a card have been bought. The game is highly customisable based on the choice of which 10 cards will be available. But in many games like Ascension or Star Realms (both of which by the way have excellent free mobile app versions) the market is a row of cards randomly drawn off the top of the deck, with a just a couple of basic always available cards as a chance mitigation mechanic to ensure you can still buy something if the cards presently in the row happen to be expensive. This mitigation, however, is only really helpful early on in a game, and even with it the row structure introduces significantly more randomness to a game compared to those with fixed piles (especially in Ascension as enemies are also mixed in with the shop). And this can be a problem because it amplifies the randomness inherent in when your cards come out of your deck, a randomness that effects how big a buy or how powerful a combo you can make in each turn (which is why cards that let you draw more cards are so valuable).

Difficult Ascension situation

In this game of Ascension my efforts had resulted in an unusually high number of currency (and like in most deckbuilders you lose whatever you haven’t used at the end of turn) but the market row only presented me with a puny 1-cost card to buy, because the rest of the cards drawn were monster cards.

Games with these random rows are not necessarily badly designed- more randomness can always add variety and excitement. Being able to block an opponent from buying certain cards also makes purchase decisions more interesting, as if you didn’t have that consideration you might always be best off unthinkingly buying the most expensive card you can. But Dominion ensures these decisions are interesting without increasing the randomness of the game because the functions of the cards are more diverse, with few of the cards being worth points. Hence you might be able to afford an expensive high-scoring card, but seeing as it does nothing each time you draw it, you may prefer to buy cheaper functional cards to build your engine instead of adding to your end-game score yet. But in these other games one player will often by chance gain the unfair advantage of having better cards available to buy on a few of their turns, and can become a ‘runaway leader’ if this happens early on.

A couple of competitive games that do something interesting with the market are The Quest For El Dorado and Arctic Scavengers. El Dorado is a race where you build your deck to be able to move at speed over a variety of terrain. Its market combines fixed piles of certain cards with new cards that can come into the market, the twist being that once a pile is depleted the next player to buy can then choose any of a much wider range of cards to purchase, but whatever they buy will then fill the empty spot in the market, becoming available for other players to buy too. I think this is a really neat solution to the problem we’ve discussed because it combines the variety and freshness of a chance draw with the fairness of fixed availability. Arctic Scavengers, on the other hand, literally combines them, having a market you can always hire mercenaries from and a scrapheap where you can push your luck to find something useful rather than junk. What makes this more interesting is that unlike most deckbuilders, you can only use one of the values on each card, which creates tighter decisions as you chose which cards (if any) you should use for hiring, scavenging, or fighting.


Deep Blue has an innovative system for cycling the cards you acquire with less randomness

Some games take on engine building mechanics from deckbuilders while distancing themselves from their ancestry with randomly shuffled decks. In the co-op game Aeons End you don’t have to shuffle your deck meaning that to some extent you can program which cards will be re-drawn together. In Deep Blue and Century: Spice Road you still gain more cards that you can then play multiple times in the future, but these go into your hand, and you can choose when to play them- and after you have, when to take them back into your hand again (for the cost of an action). I suppose this mechanic is something in-between a tableau builder and a deck builder, which we might call a hand builder. Such mechanics are great because they increase player control relative to random chance.

Assessing Engine Building

All games need action selection mechanics, but not all games require engine building. The key attractions of engine building are 1) giving the game a more exciting sense of pace, 2) introducing more options and replayability, 3) adding strategic depth by creating a kind of ‘game within the game.’

These could be the goals of adding engine building mechanics to a design, but they don’t always have these effects. Getting shot in Colt Express is a kind of ‘negative deck building’ as your deck, and potentially your hand, gets riddled with bullet cards that are no good for anything. So while normal deckbuilding is great example of how engine building keeps gameplay fresh over its duration as your turns become more powerful, in Colt Express the pace actually slows as you succumb to your wounds. Of course this effect is intended by the game -getting shot is bad!- and it’s cleverly thematic.

Funny Colt Express situation

Playing Colt Express on I (green) suddenly had easy access to all the loot but I’d been shot so much earlier on, that even with an extra card I couldn’t pick any of it up!

This kind of negative deckbuilding works better in my favourite racing game, Flamme Rouge, because although the cards that you have in hand cycle through your deck, here you can only play each of your cards once in the game. This means that despite your deck getting polluted with fatigue cards, you are in control of how many good cards you’ve saved to use later. So hopefully your pace will not stagnate as you come to the final stretch of the race, and in my experience the competition is intense enough that it would be exciting even if the cyclists were sluggish and breathless as they approached the finish line.

But neither of those two are at all what we’d call ‘engine building games’, games typified by Scythe, where you have many different actions you can improve the efficiency of performing. But this dynamic of escalating power doesn’t necessarily give a game an engaging sense of pace. Indeed, while Scythe is a very popular game, I personally find it too slow and monotonous because your actions are so limited until you’ve spent the whole game improving them. And once I’ve spent the game, the game is over, and that’s generally before I’ve had as much chance as I’d like to reap the benefit of what I’ve worked on. In other words, it seems that in a game of Scythe the beginning goes on for most of the game, then the middle briefly flashes past and abruptly the game ends. This is not a problem if you find all that engine building ‘beginning’ enjoyable irrespective of getting to use it, but I don’t. Whether or not others agree with this assessment of that game, it’s important that engine building mechanics are designed to make the game as a whole more enjoyable, and you don’t simply make the gameplay stilted so that players will feel the sense of pace when it speeds up later. You want to give the player the dilemma of whether to carry on using their actions to build their engine, or whether it’s time to start running their engine and reap its benefits before the game ends.


The game has popularised the use of individual player boards, which are useful for keeping track of the engine one is building. 

Another potential downside to engine building mechanics is that they are particularly susceptible to the runaway leader problem. If one player builds a much better engine than the others to start with, this can act as a ramp up to reaching a ‘higher level’ in the game sooner. This advantage can act like a multiplier; turn on turn it can be compounded into an unassailable lead. As previously discussed, this sometimes happens in deckbuilding games when a player gets some great cards early on and hence can use them many times, although that is only really a problem in competitive games. There are quite a few deckbuilders, most popularly Marvel Legendary and Harry Potter: Hogwarts Battle, which are cooperative games (meaning that the players play as one team to beat the game’s challenges) and if one of you gets more powerful by chance that doesn’t ruin your experience as you are teammates anyway. Other types of engine building game often use worker placement, which is not so suited to co-op games as it involves limiting other players actions.


Atlantis Rising (2nd edition pictured) is a rare example of a co-op worker placement game, where instead of thinking about which action spaces your opponents want to take, you have to weigh up the risk/reward of moving workers to spaces that the game might flood and destroy.

Thankfully, managing the runaway leader problem does not require that games designs avoid competition itself, but only the most aggressive type of competition. Namely the type in which the more one player gains, the more is lost by the others- a ‘zero sum game’. Engine building works well in Euro games because they have a softer form of competition with less fighting and direct interaction between the players. The emphasis is more on puzzling-out the best actions to take for improving your own score, than it is upon controlling the board or eliminating enemy pieces. Everyone can carry on playing because no one gets eliminated part way through, and specifically, no one is prevented from being able to make satisfying progress as they play.

If someone is beating you at Chess their progress comes at the expense of your own- you have less valuable pieces left to use than they do. And not being able to achieve much makes a match unsatisfying, particularly if the difference in skill between you makes it unlikely you’d achieve more in more matches against them. Conversely, having an opponent who is beating you in a Euro game like Tzolkin is unthreatening because you can still puzzle-out the moves that work best for your engine –for the approach you’ve taken and keep adding to your score. You may still never beat a player who is much better than you, but that doesn’t prevent you from beating your own previous scores, and you can enjoy the ‘puzzle’ of the game just as much as if you did win. This synergises well with engine building because you get the upsides of the crafting your own approach, while the softer competition mitigates the downside that some players may leap ahead. Cooperative games share with Euros this feature of being fun even if you’re not beating others, which is the biggest innovation in games design since the millennium, and one cause of the titanic growth of the modern hobby.


Return to parts:

1 – Play

2 – Action Points

3 – Action Drafting

4 responses »

  1. Pingback: Philosophy of Tabletop Game Design: Action Points | Vibrant Bliss

  2. Pingback: Philosophy of Tabletop Game Design: Action Drafting | Vibrant Bliss

  3. Pingback: Wingspan and Post-Capitalist Forms of Competition | Simon McNeil

  4. Pingback: Splendor Isn’t Splendid But Golems Are Pretty Cool – Utter Omnishambles

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