ZeroCrewA Flags game
The Flag Theory Game
Pick a passport, a home, and a company. Then spend one year planting your flags around the world, and see how much more you keep than if you had stayed home.
What is flag theory?
Flag theory is the idea of spreading your life across countries: citizenship in one, tax residency in another, a company in a third, and the places you enjoy living in others, so no single country controls all of it.
The game turns each flag into a decision. You choose three before the year starts and plant the rest as you go.
- Citizenship. Choose from 22 passports. An EU passport lets you live anywhere in the EU with no day limit. Other passports count Schengen's 90/180 days, and a US passport also means US tax wherever you live.
- Residency. You start registered where you live today. Rent an apartment somewhere else and you can register there instead, which ends your old registration. Registering in a Schengen country gives you a residence permit there, so days in that country stop counting toward the 90.
- Business. Your MRR, from $5,000 to $1,000,000, your monthly growth, your profit margin, and where your company is registered: a Delaware LLC, a UK Ltd, an Estonian OÜ, a UAE free zone company, a Cyprus Ltd, a Singapore Pte Ltd, a Hong Kong Ltd, an Andorran SL, or no company at all.
- Homes. An apartment costs rent every month, even while you're away, and a home can make you tax resident. Germany, for example, can count you as resident because of a home you keep, whatever your days.
- Playgrounds. The cities you visit to live well. Good vibes grow your MRR faster.
Residency rules in the game
At the end of the year every country checks your days, your homes, and your registration. When two countries both claim you, the tax treaty picks one, following the OECD model treaty: first where you have a permanent home, then where you registered and centred your life, then where you spent the most days. If no country claims you, the country where you're registered keeps you.
| Country | You become resident when | Income tax | Dividend tax | Company tax | Source |
|---|---|---|---|---|---|
| United Kingdom | 183 days, or your only home is here and you spend 30 days in it. If you lived here last year, fewer days count when you keep ties such as a home. | 45% | 39.4% | 25% | HMRC |
| Germany | A home you keep and use makes you resident, whatever your days. Otherwise an unbroken stay of six months. | 47.5% | 26.4% | 30% | German Fiscal Code, §§ 8-9 |
| Portugal | More than 183 days in any 12 months, or a home here you mean to keep as your main home. | 50.5% | 28% | 20% | PwC |
| Spain | More than 183 days in the year, or your main business and interests are here. | 47% | 28% | 25% | PwC |
| Switzerland | A home you mean to live in, or about 30 days in a row while working here, or 90 days without working. | 39% | 22% | 19.6% | Swiss Federal Tax Act (DBG), Art. 3 |
| Andorra | More than 183 days, or your main business and home are here. Entry is only through Spain or France. | 10% | 0% | 10% | Andorra income tax law 5/2014 |
| Cyprus | More than 183 days, or the 60-day rule: 60 days, a home and a company here, and no more than 183 days in any other country. | 35% | 2.7% | 15% | PwC |
| United Arab Emirates | 183 days in 12 months, or 90 days with a residence visa and a home here. | 0% | 0% | 9% | UAE Ministry of Finance |
| Georgia | 183 days in any 12 months. Income from abroad isn't taxed. | 20% | 5% | 15% | PwC |
| Thailand | 180 days in the year. Foreign income earned since 2024 is taxed when you bring it into Thailand. | 35% | 35% | 20% | PwC |
| Hong Kong | No residence test for tax: it taxes Hong Kong work and Hong Kong profits. More than 180 days makes you resident for tax treaties. | 15% | 0% | 16.5% | Inland Revenue Department |
| Singapore | 183 days in the year. Foreign income you receive is mostly tax-free. | 22% | 0% | 17% | IRAS |
| United States | Citizens owe US tax wherever they live. Visitors: about 183 days, counting part of the two years before. | 37% | 23.8% | 21% | IRS |
| Romania | More than 183 days in any 12 months, or your domicile or the centre of your life is here. | 10% | 16% | 16% | PwC |
| Estonia | More than 183 days in any 12 months, or your permanent home is here. E-residency doesn't count. | 22% | 0% | 22% | PwC |
Rates are single numbers for a founder taking about $250,000 of profit, at the top rate in most countries. Real tax systems add allowances, brackets, and social contributions. A company in a lower-tax country that you run from your laptop at home can be taxed where you live, so in the game it needs 60 days at a base in its own country. The game counts a calendar year everywhere, although the UK's tax year starts on April 6. The other countries in the game share one set of rough rates and a plain 183-day rule, because their real rules weren't checked. The game doesn't model visas, so for now you can pick only passports that enter Schengen without one.
How the score works
- Your MRR grows every month by the rate you set. Vibes above 70 add 10% to revenue, and vibes under 30 cost you 15%.
- Your company keeps the profit margin you set, 80% unless you change it.
- Living costs, rents, and internet speeds come from Nomads.com. You pay short-stay prices while you travel and local prices at your own apartment.
- At the end of the year the game finds your tax home and charges company tax, then dividend tax, or income tax if you have no company. US citizens also owe US tax.
- The game plays the same business for a year where you never left home. The difference between the two is your score.
Count your real days
In the game the counters run for you. In real life, the Flags apps do it.
Flags Schengen
Stay inside the Schengen 90/180 rule. See the days you've used, the days you have left, and the day you need to leave.
Flags Tax
Count your days in each country so tax residency never surprises you, and learn how the rules work. Education only, not tax advice.
Flags Map
Your countries-visited map, filled in from the dates and places your photos already store.
Questions
What is flag theory?
Flag theory is the idea of spreading your life across countries so no single country controls all of it. The classic flags are citizenship, tax residency, a business base, where you keep your assets, and the places you live for fun.
Does registering in a country make me tax resident there?
Not on its own. Each country has its own test, usually based on your days there and whether you keep a home there. In the game, registering ends your old registration, but the new country still has to catch you with its rule, and a home you keep elsewhere can still pull you back.
What happens if two countries both say I'm resident?
Tax treaties break the tie. The first test is where you have a permanent home. If that doesn't settle it, the treaty looks at where your personal and economic life is centred, then where you usually live, then your nationality.
Can I be tax resident nowhere?
Rarely in practice. Many countries keep taxing you until you prove you've left, and banks and tax offices ask for a tax residency certificate. In the game, if no country's rule catches you, the country where you're still registered keeps taxing you.
Is the game tax advice?
No. The rules are simplified versions of real tests, and the rates are single numbers standing in for whole tax systems. Use the game to learn what the rules look like, then check your own situation with a professional.
Where do the city costs come from?
The cities are the Nomads.com top 100, plus a few the game keeps for their tax rules, such as Dubai and Limassol. Living costs, rents, and internet speeds come from Nomads.com, taken on October 9, 2026.
City data from Nomads.com, taken on . Rules checked on . Simplified game rules, not tax or legal advice.