Mechanic Archetypes – Pool Builders

Written by Alex Harkey

poolbuildersOur latest topic is “Pool Builders”, a collection of related mechanics like Deck Builders, Dice Builders and Bag Builders that are worth exploring side-by-side as they tend to share similar strengths, weaknesses and approaches to game design.

The most visible difference between these categories is the components they use, so we’ll often use terms like tools, resources and objects to collectively refer to the various components that comprise a player’s deck, bag or dice pool.

In this article I’ll introduce many of the key traits we can find in games that are described as pool builders and in our following articles we’ll explore the key strengths and weaknesses of the group of mechanics. In our concluding segment we’ll finish up with our observations of dozens of pool builders, showcasing some of the most innovative and brilliant ideas we’ve seen in game design that incorporate these mechanics.

What are Pool Builders?

At a high level, our ongoing exploration of game mechanics has developed into its own rank-based taxonomy. If Dominion or Ascension were considered species, their genus would be Deck Builders and their family rank would be Pool Builders in a classification hierarchy. If we’re being completely accurate, “Pool Builders” would probably also go by a fun Latin phrase like stagnum aedificantes.

When we explored Worker Placement, we thought it was worthwhile to revisit exactly what the mechanic is, since games that simply use the term “workers” (Terra Mystica, Puerto Rico) and games in which you add or remove meeples (Carcassonne, Five Tribes) are often curiously grouped into the definition.

An exact definition for pool builders is challenging to pin down since it’s both an expansive term and one that continues to evolve as new games continue to push existing boundaries. Rather than spending ten paragraphs too many to argue the merits of an overly precise definition of “pool builders”, I’m going to identify many of the core characteristics with some examples.

What do Pool Builders ask us to do?

Despite all the variety in mechanics, components and ideas we see in the category, pool builders consistently embrace the feeling we describe when we discuss “building an engine” in games;

  1. We start with a standard set of tools; the cards in Dominion, dice in Quarriors and cubes in Automobiles.
  2. We reinvest the proceeds from each turn back into our in-game livelihood, adding to and upgrading our standard tools.
  3. We carefully select our upgrades to target synergy with our existing tools in order to improve our future potential.

We Manage Long-Term Efficiency

bbgreenMore than most game mechanisms, pool builders are quests for long-term efficiency; each turn I’m seeking to maximize the circumstances I’m given in a manner that will maximize my effectiveness in the turns to come.

These games are rarely about organizing that game-changing turn that shifts your momentum from follower to front runner, nor are they about taking big risks to go from long shot to leader. Success in these games is achieved by pacing your strategy over many turns; a methodical slow and steady grind.

automobilesEvery turn can seem to have almost a marathon mentality; making incremental steps toward a finish line you won’t be able to see until much of it is over. This racing competition can carry through to many endgame conditions, as players have the urgency and incentive to rapidly deplete the province cards in Dominion, reach the Pacific coast in Lewis & Clark or be first across the finish line in Automobiles.

While efficiency would seem to be ubiquitous in modern game mechanics, it’s occurrence is actually not all that common. In fact, surprisingly few gaming mechanics actually emphasize a methodical turn-by-turn efficiency at all:

airlineseuropeIn contrast to pool building, mechanics like stock holding and simultaneous action selection emphasize the timing of actions, as success is tied to taking an action at the right time to get an optimal outcome. A game like Airlines Europe isn’t about simply taking over and controlling the top performing company; it’s about letting other players invest in that company, then taking it over just before a key scoring moment. You can be the least efficient player and the best player if your timing is impeccable.

tammanyhallIn take that and area control mechanics, the decision variable is largely about who you target with a given action. Top performers are rarely just the players who handled their situation the best, they are often the ones who were least targeted by opponents. If anything, demonstrating efficient play over a large number of territories early in Tammany Hall or Small World is sending out an invitation that you would be a lucrative target next round.

If we’re going to argue that efficiency is king, then there must be inefficiencies out there that players should avoid. In pool building games, the order in which you acquire new cards or tools is at least as important as what you acquire.

orleansYour earliest acquisitions will either set you apart or set you back in pool builders and while there are relatively few terrible decisions you can make, this can sometimes result in standard or “automatic” openings to games which can detract from the relative freedom they initially present. The presence of the Chapel in Dominion can potentially overshadow the other options available and its hard for me to argue that there are more than a few efficient openings in a game of Orléans.

We Manage Uncertainty

bbblueAs many new games continue to gravitate toward lower luck and more complete information, pool builders embrace a style of controlled randomness all their own – they are an intentional platform for providing variance in the tools and resources we use to build our engines.

Builders rely on the variety of the draw, the randomness of the pull and the composition of elements we accumulate each turn. While the precise makeup of the menu of items we use on a turn may not be under our control, the mechanic encourages an interesting style of “semi-open” information: all the players may know what is exactly in my deck/bag, but no one, not even I will know exactly what my next draw is going to look like.

AscensionFollowing Dominion, games have gravitated toward additional unpredictable elements; Ascension introduced a branch of deck builders that use constantly moving central row of cards that players purchase from. Now not only was your own deck producing an unpredictable output, but the purchasable assets each turn were as well. It extended an ongoing layer of player interaction as decisions emerged like “Should I grab that card just so Matt can’t get it on his turn” while also making the mechanic more reactive and tactical in approach.

dborangeDice building games probably epitomize the most frustrating yet exciting characteristic of the group; getting access to the right resources at the right time. Once you’ve acquired the dice (perhaps for a specific ability or combo), you need to roll the right outcome at the right time to achieve any specific intentions you may have planned.

Builders have never been about masterminding how the next five turns play out or anticipating your opponent’s next three moves and performing them one turn earlier. Builders are about maximizing your current situation and doing that better than anyone else at the table over the course of the game. Not every turn may be pretty, but the most successful players will find efficiency even in the most frustrating “Are you kidding me?” -type turns.

Some adversity in gaming is entirely self-inflicted

Adversity in gaming can be entirely self-inflicted

One way we often mitigate uncertainty in games is through redundancy. Rather than hoping to draw that specific card or harmonious combination at the right moment, we double and triple up on acquisitions to improve our odds. In fact, adjusting the concentration level of our resource pool is one of the few things we actually have complete control over in pool builders.

We Manage Encumbrances

dbpurpleThe nature of pool building encourages players to acquire more things, often improving the quality of the tools in our deck or bag while (as a byproduct) increasing the quantity of tools in total. This is a motivation already ingrained in gaming; typically we are making progress if we accumulate more things on our turn, even if those things don’t have an immediate purpose. But pool building spins this assumption into one of its own: more is not always better.

DominionIn the question of quality versus quantity, pool builders are overwhelmingly oriented toward quality of resources. This is due to the use of hand limits as a means to influence strategic choices. Dominion‘s five card hand ended up setting a precedent for every game to follow in its wake.

Of course hand sizes or limits have been around in games for seemingly forever and they are a card game’s approach to an inventory management system. By having a limit to how many things you can manage at once, you’re eventually going to miss out on some pretty valuable things.

In the context of deck and pool builders, new acquisitions often render old acquisitions with a degree of obsolescence; old resources become an ever-accumulating weight that hinders progress and presents a new hurdle to jump. Other mechanisms allow unproductive resources to sit idle and conveniently out of the way. In pool builders, they come back to haunt you. Then they do it again every few turns until you get agitated enough to get the mafia to anchor them with cement.

Dominion also introduced the brilliant idea of making VP cards an impediment to your normal turn, a trait that leads to a natural pivot point during the game and one of it’s best decision points: When should I stop acquiring better action cards and start chasing VP?

thunderstoneThe question of what to do with victory points in deck builders has led a multitude of answers. In some ways Thunderstone tried to avoid it, as the monster/VP cards frequently provide some sort of benefit in future turns once added to your deck. Other games like Ascension have made practically every card worth some point value and others have made everything you built during the game worth nothing.

Allowing players to manage encumbrances is an area of strategic intricacies and one we’ll revisit in our third article of this series when Matt looks at observations and innovations across a wide range of pool building games.

We Manage Expectations

dbredIf there is an ideal balance between how much of a game’s outcome is determined by luck and skill, I think pool builders have to be pretty close to it. For all the complaints I’ve heard about the existence of luck in games, the complete absence of it tends to be a pretty terrible playing field for players of drastically different skill levels.

The uncertainty in these games can provide an enjoyable experience for a variety of skill levels. While long-term efficiency will win out in the end, the occasional perfect combination of cards in hand provides a pretty memorable highlight for a new player; a small victory that motivates that player to keep going. At the same time, the possibility of subpar draws keeps the thrill of unpredictability alive for experienced players who are still tested to make something happen with what they have.

Pool builders still manage to separate skill levels effectively by narrowing the field of players to those that can put together a strong composition within their resource pool. But it also doesn’t determine exactly who wins, as the variance of the draw can fluctuate your chances between victory and defeat. As a result, victory goes to one of the better performers, so you have a deserving winner, but the outcome isn’t foreseeable before the game begins.


While key elements of pool builders have existed in games for decades, it would be challenging to not point at the emergence of Dominion and deck builders as a starting point to explain the growth of these game types.

It also means it is nearly impossible to introduce pool builders without a disproportionate emphasis on deck building games and its ideas. Deck building has just been explored significantly more by designers than its offshoots. We’ll be giving the other categories of pool building plenty of attention in later segments and we hope you’ll weigh in on the discussion.


4 comments on “Mechanic Archetypes – Pool Builders

  1. Carl King

    Very great post. I simply stumbled upon your blog and wanted to say that I have really enjoyed browsing your blog posts. Keep posting and keep sharing like this.

  2. Tonichi Sanvictores

    Thanks for getting into this sort of discussion! I think the bag-building mechanic is not yet thoroughly represented (definitely not in the same level as deck-builders), and more research/thought is needed to further develop this area. On to the next article!

  3. Jonathan Jordan

    I am so happy that you are focusing on this genre of game right now. It feels serendipitous that this series is going up just as I am focusing on designing two different pool builders (one a deck builder and one a bag builder). I look forward to your analysis of these games.

    1. Alex Harkey

      We’re thrilled to hear it Jonathan and we hope you’ll join us along the way and question our assumptions.

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