The following is an excerpt from the Designer Notes for Old World. The game, a historical 4X set in classical antiquity, released on July 1, 2021, and is available for purchase here.

The technology tree was one of the great innovations of the original Civilization, without echoes in Empire or other proto-4X games. (Interestingly, the closest parallel is probably the technology card discounts in the Avalon Hill Civilization board game, which Sid has always maintained was not a big influence on him. Bruce Shelley certainly would have been familiar with it, and a great piece of Civ trivia is that the artist of the original Avalon Hill technology cards, released a decade before Sid’s Civilization, was none other than Brian Reynold’s uncle!) The tech tree was a perfect bit of game design, especially if the goal was clarity. It was always abundantly clear how to discover Gunpowder if you wanted to build Musketeers.

Of course, every piece of game design is a set of trade-offs, and one of the trade-offs that the traditional tech tree made in the name of clarity was determinism. As everyone knew the path to Gunpowder, it was very easy to remember the exact order of the ten techs which led to Gunpowder so that the player could get to it as early as possible. If this strategy turned out to be optimal, then a veteran player would find themselves making the same choices, game after game after game. Indeed, many versions of Civ made this even easier for the player by allowing them to target a specific tech and then highlighting the right choice each time it came up.

In fact, Sid anticipated this problem from the beginning as the technologies presented to the player in Civ 1 were a random subset of the ones available. However, because this version had no in-game UI and because the tech tree itself was so new, players didn’t give this randomness much thought, especially when it was dropped quietly in later versions. Giving players a random subset of tech choices did solve the basic problem but was perhaps an inelegant way of addressing it. The ideal solution would force players to make difficult choices while also being transparent about why the player couldn’t choose from all the valid options.

The answer came from borrowing mechanics from deck-building board games, first popularized by Dominion in 2008, which made shuffling, drawing, and discarding cards an important part of gameplay. For Old World, each tech would be represented by a card, and the player would choose a tech by taking four cards from the current draw pile, choosing one, and discarding the rest. The discarded techs would not be seen by the player again until the next time they would be shuffled through the deck, guaranteeing difficult decisions. Deciding between Forestry and Labor Force becomes more meaningful because the technology that you don’t pick will not be available until it passes through the discard pile, gets shuffled into the next draw pile, and is eventually drawn back into your hand, which could require researching 3 or 4 other techs first. The player can follow the path of each card through the different piles to know exactly when it might next be available and what the odds are of drawing it. Thus, there is no longer a golden path through the tech tree, each individual choice is more meaningful because of discarding, and the whole system is completely transparent to the player.

As is often the case with new game systems, making one change often opens up new possibilities that didn’t make sense beforehand. Turning techs into cards is a good example of this phenomenon because once we had the card metaphor, we could shuffle other cards into the deck which were NOT technologies but could still be unlocked the same way techs would be. Thus, we added “bonus” cards to our tech system, which could be researched just like regular techs but would provide a one-time bonus instead, like a free Settler, a Great Scientist, or a boost of Stone. The bonus cards would only be available once for the player, so they would be, using the terminology of deck-builders, trashed instead of discarded because we didn’t want to clog up the deck with bonus cards for players who preferred to focus on just standard technologies. These cards added a nice apples-to-oranges comparison for players to make – take the short-term bonus (a free archer right now) or the long-term option (unlock Lumbermills to produce Wood to build multiple Archers). Strategy games benefit a great deal from borrowing mechanical metaphors from physical board games – not only do many players already bring an understanding of the system with them but the physical roots of the mechanics also make them inherently easier to explain on the interface.