A guide for playing on Master difficulty.
Master difficulty is nothing like easier difficulties. It’s also the most fun I’ve ever had playing an Anno game. I’m just going to be talking about broad strategy, other people have done an excellent job of covering the basics.
There are three major challenges introduced by Master difficulty. The first is all or most AI will usually be at war with you, meaning the only way to occupy an island is to either colonize it first or conquer it. The second is the AI plays fast and aggressively colonizes. There will be no free islands after the first hour or two of game play. The third challenge is you cannot move buildings, even in blueprint mode. This forces you to be precise and can really slow you down. While it would be hyperbolic to say seconds matter, minutes really do.
Phase #1: StarCraft – City Building Edition
In the first phase, lasting for a couple to a few hours, you need to be building houses as fast as you can. Your first island can comfortably support about 400 houses. If your playing the campaign getting to iron is a priority, but in order to colonize and start producing beer you should buy iron from Mr. British so you can grab a couple of islands that produce hops and bricks.
In this stage optimized layouts are a must. There’s no time to carefully squeeze a production block into a marginal space. Every production chain needs to be self-contained. The exception is "feeder islands.” These islands will likely have only farmers harvesting what your main island needs. On this point its important to overbuild schnapps because feeder islands either won’t have potato fertility or will be so small you need the space for a more valuable production.
In order to sustain the pace of building necessary to outpace the AI you need 8 sawmills and six brick kilns working continuously as soon as possible. You’ll likely want to have a clipper loaded up with basic construction resources that can be moved around to enable production on feeder islands. Feeder islands usually can't be self-sufficient.
Three hours into the game you should have two or three feeder islands and two large islands. Your income should be net positive by a couple thousand.
Phase #2: Fortress Islands
Phase 2 starts when the AI declares war on you. The AI will attempt to conquer poorly defended islands and target your trade routes. You’ll need to fortify your islands with two to three turrets each. There should be at least one turret along every section of coast. The AI is a bastard and will shell your island from sections of unprotected coastline.
You can delay war by not using propaganda, gifting money, and attacking pirates. I found this was less effective than having a higher military score than the AI. The AI counts all your defenses collectively when determining your military strength, so if you have enough defenses to outclass them, they will be less likely to declare war, even though they will certainly have a larger navy that could take any one of your islands.
This is the phase where you want to have a big fleet. I've been happy with two three frigates and two ships of the line. This is enough to squash most AI fleets and deal with pirates. It's useful to engage in some piracy. The AI cheats and gets Epic and Legendary items frequently. Sinking their ships will often net you extremely useful items that would would cost 100,000+ to buy. There may also be feeder islands that you will need for T4 and T5, take them sooner rather than later, even if all you do is squat on them with some turrets. If you can, you should also seize islands that could block your trade routes even if they don't produce anything you need.
When you attack an island be sure to take it. The AI will quickly fortify islands if they are attacked unsuccessfully, usually adding three to four turrets. By hour five or six the AI will start laying down Big Bertha turrets, meaning it won't be possible to conquer that island until you have steamships.
Once your position is secure and you have the ability to produce all the resources you need you should be safe until the AI starts building steamships.
Phase #3: Teching Up
In this phase you will be largely focused on generating income and reaching higher tiers of tech. As a guiding principal, the gains you get from optimizing your islands are now always worth as much as fulfilling a higher tier need or luxury on one of your main islands. I might seem to make sense to reduce your maintenance by a couple hundred by shifting production to benefit from a really powerful item, but this will not be effective as meeting the coffee need for 1,000 Artisans. If you are in doubt, pause the game and do some math.
In my experience trade unions make the most sense on feeder islands. It takes a lot of time to reformat existing production on large islands to benefit from trade unions. In my games I've shifted some farming production from the main islands to feeder islands so that I can upgrade more houses to workers and artisans. Trade Unions with items can make that process more effective.
I recommend selling most of your fleet to achieve higher income. A battle fleet will cost up to 2k to maintain, income that would be better spent on items that can reduce expenses and accelerate growth. In my games the AI has built enough turrets that wooden ships can't take them except in unmanageably large numbers. The path finding for fleets is terrible, and you actually have to micro you’re ships in order to get them to engage sensibly with enemy defenses. It's very easy to lose a large fleet by engaging badly and allowing enemy defenses to sink a warship before your navy is fully engaged. However, don't forget to keep producing ships of the line non-stop. They sell for 50K and at this point you won't be spending sails and cannons on anything else.
Until the AI get's steamships, a few turrets are more than enough to keep you safe. The AI is smart enough not to go close to an island they can’t capture. This means islands create a zone of safety within the range of their turrets. It also means that if the AI attacks and island, they can take it. This also means that adjacent islands effectively protect each other, and that you can effectively seal areas of the map off from AI you are at war with. It’s especially important to adjust your trade routes to take advantage of this. Keep a close eye on your notifications. If the AI is stupid and suicides a ship on your defenses you can take their floating cargo.