Portugal Civilization Guide (Civ 6): João III

Portugal is the most map-dependent civilization in Civilization VI, and it isn't close. On an Archipelago or coastal-heavy map, João III runs the single strongest trade economy in the game — international routes with +50% to all yields, extra range over water, and a unique ship that turns foreign cities into permanent trade bonuses. On a Pangaea or Highlands map, Portugal is arguably bottom-tier: its core ability literally cannot function without coastal cities to trade with, and no amount of skill fixes a landlocked ocean empire. Before any strategy in this guide applies, check the map. Everything below assumes the map gave you water.

Quick Facts

Leader	João III
Civilization Ability	Casa da Índia
Leader Ability	Porta do Cerco
Unique Unit	Nau (replaces Caravel)
Unique Building	Navigation School (replaces University)
Unique Improvement	Feitoria (built by Nau in foreign cities)
Starting Bias	Tier 1 toward Coast
Best Victory Paths	Any — the trade economy funds all of them
Weakest Path	Everything on land-locked maps
DLC required	Portugal Pack (New Frontier Pass, March 2021)

Civilization Ability: Casa da Índia

• International Trade Routes can only be sent to cities on the coast or with a Harbor, but gain +50% to all yields. The restriction is severe — per the Wiki's strategy notes, Portugal effectively sends maritime international routes only, and traders can't cross more than a tile or so of land to reach their destination. The payoff is the largest trade multiplier any civ gets: every yield on every qualifying route, multiplied by 1.5.
• Traders have +50% range over water, and can embark as soon as they are unlocked. Your trade network reaches cities nobody else can trade with in the early game, across ocean that grounds other civs' routes entirely.

The design intent is clear: Portugal trades with everyone, everywhere on the coast, and converts one commercial district into what would take other civs two. The design cost is equally clear — on maps without enough coastal targets, Casa da Índia is a dead ability, which is why Portugal's tier placement swings more with map type than any other civilization's.

Leader Ability: Porta do Cerco

• +1 Sight for all units. A full extra tile of vision on every unit, army and navy alike. For an exploration-and-trade civ this is quietly excellent: your scouts see farther, your trade ships spot threats earlier, and your Naus (3 base Sight) see four tiles out.
• Meeting another civilization grants +1 Trade Route capacity. Exploration literally prints trade routes. Every new face on the map is a permanent economic slot — which is why Portugal scouts harder and earlier than any other civ in the game.
• Open Borders with all city-states. Your scouts and traders walk through city-state territory freely, which accelerates the meeting-everyone engine and keeps trade lanes open without diplomatic effort.

João III's agenda (Navigator's Legacy) mirrors this: he loves civs that explore and dislikes those that don't. Play like the agenda — the whole kit rewards being first to know the map.

Unique Unit: Nau

Replaces the Caravel, unlocked at Cartography (Renaissance Era).

Stat	Nau	Caravel
Combat Strength	55	55
Movement	4	4
Sight	3	3
Cost	240 Production / 960 Gold	240 Production / 960 Gold
Maintenance	2 Gold	4 Gold
Upgrades from / to	Galley → Ironclad	Galley → Ironclad

Abilities: one free Promotion when first trained, purchased, or upgraded into; 2 build charges; and the defining ability — can construct a Feitoria (consuming one build charge). At half the Caravel's maintenance, a Portuguese navy is cheap to keep afloat, which matters when your strategy wants Naus sailing to every foreign coastline on the map.

The free promotion and spare build charges have useful side effects: a Nau with a charge remaining can clear and repair improvements for free, and can spend a charge to clean up nuclear contamination. But the ship exists for one reason — building Feitorias.

Unique Infrastructure

Navigation School (replaces University)

Unlocked at Education (Medieval Era); requires a Campus with a Library. 250 Production, 2 Gold maintenance.

• +25% Production toward naval units in this city
• +1 Science for every two Coast or Lake tiles the city works
• +1 Great Admiral point per turn
• Plus standard University benefits: +4 Science (boostable by Rationalism), +1 Housing, +1 citizen slot, +1 Great Scientist point per turn

In a coastal empire, the per-coast-tile science adds up fast, and the Great Admiral points stack across every Campus you own — Portugal routinely claims admirals it never competed for on purpose. Build these everywhere; they're a University upgrade with no downside.

Feitoria (unique improvement, built by Nau)

• Can only be built by a Nau, in a foreign city, consuming one build charge.
• Each Feitoria adds +4 Gold and +1 Production to Portuguese Trade Routes that end in the Feitoria's parent city.
• Note: per the Wiki, the Feitoria has fairly restrictive placement rules — treat prime Feitoria spots as something to scout for, not assume.

Do the math: a trade route to a city where you've planted two or three Feitorias, multiplied by Casa da Índia's +50%, becomes one of the richest single yields in the game. The loop is the whole civilization: Naus sail out, seed Feitorias in every friendly coastal city, and your trade routes harvest them forever. Protect the routes — a war that kills your traders kills your economy.

The Game Plan

Turns 1–40. Scout with everything, immediately — the +1 Sight and free city-state Open Borders make your first scout the most valuable unit on the map, and every civilization it meets is a trade route slot. Settle on the coast (tier-1 bias will help) and beeline early Harbor infrastructure in your best port cities.

Turns 40–100. Campuses up, Navigation Schools in at Education. Run every trade route you're allowed to run — international only, and only to coastal or harbor cities, so know your targets before you commit traders. Keep exploring: meeting civs is your economy's scaling mechanic. Stay out of wars; Portugal's entire game plan assumes trade keeps flowing.

Turns 100–160. Cartography unlocks the Nau. Build or upgrade several and dispatch them to the foreign cities your trade routes already serve — Feitorias are most valuable where routes already end. With cheap 2-Gold maintenance, you can afford the fleet. Use Navigation School production bonuses to keep the navy current.

After turn 160. Cash in. By now your trade network should be generating gold, science, culture, faith, and production at rates no other economy matches. Per the Wiki's own assessment, this capital funds any victory type — buy the spaceports, the rock bands, the diplomatic favors, or the army. Your only real lose condition is a coalition deciding to burn your trade lanes, so keep the diplomatic table happy and a real navy on station.

Common Mistakes

1. Playing Portugal on the wrong map. On Pangaea or Highlands, Casa da Índia is close to a blank ability. If the map generation didn't give you coastlines and coastal trade targets, restart or pick another civ — this is the one civilization where that's legitimate advice.
2. Sending traders before scouting targets. International routes only work to coastal/harbor cities, and maritime routing restrictions limit land crossings. A trader sent blind is a trader standing still.
3. Under-scouting. Meeting civilizations grants trade route capacity — the single best scaling mechanic Portugal has. If your scout died on turn 20 and you didn't replace it, you chose to have fewer trade routes all game.
4. Treating Naus as warships. They're 55-strength transports for a construction project. The Feitorias they plant out-earn anything they could pillage.
5. Starting wars. Portugal's economy lives in its trade lanes. Every war risks the routes, the Feitoria access, and the coastal cities your entire ability depends on. Win with the treasury, not the sword.

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Data verified against the Civilization Fandom Wiki (Portuguese (Civ6), João III (Civ6), Nau (Civ6), Navigation School (Civ6)) — full source list in the site data files. Reflects the final Civilization VI ruleset including Gathering Storm.

Related: Diplomatic Victory Guide · Civ 6 Leader Tier List · All Civilizations