Zero-Sum is a complex macro-economics card game for multiple players. Each player runs a country and sets financial priorities, which are then played out on a global stage with or against the other players.

A valid macro-economics model underpins the game, driven by the card choices of the players. Players can also alter the economic model to suit their beliefs or preferences.

Players can choose to go for a competitive win (financial trade balance), or a “Economic Fairness” win (those in power are responsible for providing opportunity for those less fortunate — low unemployment and low wealth gap), or an “Industry” win, or a “Standard of Living” win (low cost of living with high consumer spend). Is it possible to achieve more than one?

Rules for Zero-Sum


This is a game for up to 5 players controlling 5 countries. It can be played by 1-5 players, the app will simulate any countries with no player (Sims).

Each country has its own economy, measuring output in 7 categories: Unemployment, Wealth Gap, Cost of Living, Deficit, Corporate Profits, Consumer Spend, and Gross Domestic Product (GDP).

Each economy also has a trade balance against all other countries. Total global trade remains fixed, and each country gets a portion of that trade in 7 dimensions: Security & Infrastructure, Health & Medical Research, Arts & Entertainment (Humanities), Manufacturing, Education, Science & Technology, Agriculture. Because the total for every dimension is fixed, as one country gains in a sector, one or more others decline in that sector.

These trade balance dimensions exactly match the priorities for country spending. (NOTE: in this game, country spending is equivalent to the total spend of a country or culture, not only of government. The spend mostly reflects the values or priorities of the society.)

Play consists of selecting spend priorities and tax or tariff policy for your economy for each round (or turn). The 7 spend priorities are the same as the 7 trade balance dimensions. Tariffs are simple in this game, do not much affect trade balance. In global trade wars, tariffs mostly increase short-term profits (and inflation) but often decrease long-term global competitiveness. They are a political tool, and this is not a game about politics, so we made them unimportant, except (reducing tariffs) as a tool to reduce inflation.

The game also allows random global catastrophes. These can also be turned off for a simpler game. Players can also give financial aid to a country that is near going bust.

The country internal economics are based on a researched economic model, though the changes are generally larger and shorter-term effects than reality (which is why turns are called decades). Because economics is not deterministic and there are many different probably-valid variations to the model, the top layer of the economic model used in the game can be modified by the players.

Global trade is less realistic, a very simple zero-sum apportionment.

Each round applies all priorities and every calculation is randomly adjusted with a normal curve sampling method.

Country Economy

Priority choices have a direct effect on global trade balance, but they also affect a country’s internal economy in complicated ways, and a country loses when these get too far out of balance.

Specifically, the spend priorities affect Consumer spend, Executive salaries, Price index, Corporate R&D spend, and Worker salaries. Changes in these are then used to calculate changes in the important metrics of the country’s economy, specifically: Business profits, Consumer spending, Unemployment, Budget deficit, Cost of living, and Wealth gap.


There are five winners in each game:
Highest Overall Trade Surplus (can be changed in settings)
Highest Economic Fairness Index (unemployment and wealth gap low)
Highest Industry Index (corporate profits and GDP up)
Highest Standard of Living Index (low cost of living with high spend)

Players might instead have a goal of the longest game with no country going bust.

Hmm, I wonder if it is possible to win both highest Economic Fairness Index and highest Industry index?


Each player selects their top two priorities for spending from 7 portfolios: Security & Infrastructure, Health & Medical Research, Arts & Entertainment (Humanities), Manufacturing, Education, Science & Technology, and Agriculture.

There is a more complicated option in the settings for players to apportion their total spend in 5% increments across all portfolios.

After selecting spend priorities, the play then selects any change in tax or tariff policy. Tariffs are much simpler than real-world tariffs, they only increase prices (and revenue) and a few other minor knock-on effects. How they affect trade balance is complicated, and left for a possible future version.

When the player finishes their selections, the app calculates total country spend from any effects of catastrophes, financial aid, and tax/tariff changes. This new spend is then divided among the 7 priorities according to the player’s choices. All calculations involve a small random variation based on a normal distribution (bell curve). Changes are then applied to each economic indicator and the trade balance indicators.

When all players have finished their choices, the app runs the simulator on any Sims according to their strategies, and calculates the remaining trade balance. Remember that the total global trade for each portfolio is fixed, so any increase by one country will be matched by decreases in other countries.

Hmm, is global trade in the real world zero-sum? Economists disagree, though certainly trade is not zero-sum within any one portfolio, as modeled in this game for more interesting competitive play.

Game End

The game ends either when one or more players goes bust or after 20 decades (eg, rounds or turns). The end-game maximum number of decades is a setting you can change.Bust is when any internal economic indicator (Business profits, Consumer spending, Unemployment, Budget deficit, Cost of living, and Wealth gap), is off the chart in the wrong direction.

Financial Aid

After the first catastrophe or the first warning of a country nearing bust (whichever is first), every player will be given the option to give Financial Aid to any other country. (1 choice per turn per player).

The effect of Financial Aid is simple: 5% of the donor country’s budget is given to the other country and applied to the worst economic indicator for that country. The effect is perhaps unrealistically large, but it is important that it be noticeable in the game.

The purpose of this feature is to allow countries to prolong the game by keeping other countries from going bust.


Catastrophes affect all countries equally except for the ‘mitigating factors’. The economic effects are listed in the lower right and applied with a random value from a normal distribution.

You can adjust the probability of a catastrophe on the settings page.

The ‘mitigating factors’ are listed in the lower left of the card. Countries strong in those portfolios or economic indicators suffer less effect from the catastrophe.


Q: This is a multi-player game. Why is there no support for remote players?
A: This game plays very well with remote players through Zoom or other online meeting service. Just be sure that the host plays first, so they don’t have the advantage of knowing the plays of other players.
The main reason for not supporting anonymous remote players is that this game is designed for conversation, even collaboration. Stimulating argument about economics and the concept of ‘zero sum’ is a key goal of this game.