Costs in games are a double-edged sword. It’s easier to balance games with more costs associated with their cards/pieces/etc., since there are more knobs to turn. Yet, the more costs there are, the greater the player’s mental overhead. Adding more costs can be valuable, then, but they should be compartmentalized so that the player only needs to think about one or two of them at any point during the game.
FFG’s Netrunner is a superb example of compartmentalizing costs. Take a look at this Netrunner card, which represents a program used by the game’s hackers:
This card has three costs. First, there’s a monetary cost to put the card into play (the 5 in black in the upper left). Second, the program has a memory cost, denoted by the 1 in a chip just to the right of a monetary cost; players can normally have up to four memory’s worth of programs in play at a time, and this takes up one of them. Finally, the single pip in a row of five at the bottom-right indicates that Yog.0 costs one influence during deckbuilding.
Having three costs (separate and apart from the fourth cost to use the card’s ability) is a lot. Fortunately, Netrunner lightens the player’s load by putting the costs in separate game-stage compartments. Influence is only relevant while building a deck, and never matters during play. Cost and memory might influence deckbuilding, but they don’t have a rules-based role at that stage; they only need to be tracked precisely later, while the game is in progress. This compartmentalization means that the player only ever needs to track a maximum of two costs at once.
Of course, even two costs is enough that mistakes can be made. I once saw a video of a tournament Netrunner match in which a player had five memory’s worth of programs for the better part of the game. Neither player noticed.
Like all design rules, the rule of compartmentalization has exceptions. Starcraft, which effectively makes attention a game resource, is perhaps the classic example: we’ve all been told to “SPAWN MORE OVERLORDS” because we forgot to check how much available supply we had left. Starcraft is a fast-paced game that’s intended to test your ability to divide your focus and juggle lots of things without dropping any of them, and satisfying many costs (minerals, gas, supply, build time) is part of the challenge.
At the far side of the spectrum from Starcraft is Hearthstone:
One cost, noted in the gem in the upper-left, with a computer enforcing the rules so that you can’t forget to pay it. This is great for the more lighthearted game that I have the sense Hearthstone is meant to be, though it does put a lot of weight on the designers, who have fewer balancing knobs to turn.
Fine-tuning balance makes a designer want more costs–but every new cost is one more thing players are going to have to keep track of. Be mindful of how much effort players are being asked to expend dealing with costs, and compartmentalize them to make things easier–or, if you’re going to go the other way, be sure your game is as amazing as Starcraft. 😉