On harder difficulties, the AI can get some pretty serious advantages. An Impossible difficulty AI can hit Tier 2 on turn 9 on fast speed. Here are some quick tips I've come up with for getting those beating-AI achievements.



General Strategy

Don't go for elimination

The AI gets many many times more strategic resources than you do (x15 on Impossible Difficulty), as well as tons of science and industry. Unless you're certain you have the advantage, avoid war. The AI isn't smart enough to go to war to stop an Economic or even Diplomacy victory.



Drakken and Roving Clans are your best bet

The AI appears to have a hidden predisposition against declaring war on the Clans, and the Drakken can quickly end a war after it begins. Clans also have a few advantages (especially in their starting hero and quest techs) if you're going for an Economic victory, while Drakken do well with Diplomatic victories.



Play a solid game

None of these tips will help you if you don't know how to play. Have a plan for how you're going to win from the very start of the game, and make sure that everything you do is in service to that objective. Expand early, level your heroes, make sure your army is well equipped, etc. etc.



Manipulating the Diplomacy AI

Abuse Trades

The AI is not very bright when it comes to setting trade prices. Usually there's a particular luxury resource that they'll covet, and will happily buy more of than they'll ever need. They'll have more tech and more strategics than you - buy what you can't make.



Play them against eachother

Embrace your own smallness. If your neighbors are embroiled in a war against eachother, they'll be too busy to kill you.



Don't wait for the AI to make the first move

---AND---

Never buy treaties (except initial Peace)

Buying a truce from an AI that has just declared war on you is nigh-impossible. However, if you send regular gifts to your neighbors (keep them at "Blood Brothers" status), they'll never contemplate war in the first place. They will offer favorable deals and treaties to you. Once you're at peace with an AI, never pay for a treaty - send a small gift first, and then let them propose the treaty. I've had an AI give me a tech and an Alliance, just one turn after they would have rejected an alliance I sent them.



You can get resources from the Necrophages

The AI will happily pay small amounts for Open Borders and Market Ban Removals. If the Necrophages have a luxury or strategic that you want, you can extort it out of them in small quantities by repeatedly closing and opening borders, as long as you have the influence.



Simple Tricks

Don't be afraid to start over

If you don't like your starting spot, restart the game until you do. The AI has enough advantages without it also having a better spawn location than you.



The more techs they have, the slower they research

On Impossible difficulty, one of your biggest challenges will be preventing the enemy from achieving a Scientific victory. Simply donate a bunch of low-level techs to them once they reach T6. This will increase their research costs and buy you more time to win.



Play a custom faction

Custom factions can be significantly stronger than standard factions. If you need a little bit of an extra edge, this is an easy way to get one.



Alternatively: 1v1, play Drakken, set them to Cult, rush, and siege

Alternatively, forget diplomacy. A high-difficulty AI will be putting out settlers on turn 2 or 3 - but not if they're cult. Sieging the cult's one and only city will stifle their economy, and hopefully slow them down enough for you to keep pace. If your initial siege fails, start over and try again until it works.



If all else fails, cheese and cheat

Make them play a custom faction

Custom factions can also be terrible. There's nothing stopping you from making a faction with every negative trait in the game and no redeeming qualities. I recommend using the Cult as a basis, because a Cult without Conversion is hilariously bad.



You can win even after you lose

If you save the game and then re-load it, it clears out prior winners and allows another winner to be selected. For example, even if another faction has already achieved a Scientific victory, you can reload the save and still win an Economic or Diplomacy victory.



Play PvP instead

You'll still have to win the PvP game, but if you're playing multiplayer with no empty slots, set the difficulty to Endless. A victory in that game still counts for the achievement. Of course, if a player leaves or quits, you'll have an Endless difficulty AI to contend with, but that might make the game more interesting.

I really like that donated tech trick! I don't see how RC could win an econ victory faster than BL though. They tend to do better via military play (privateers), but the way that the AI plays eliminates that possibility. Too many garrisons, too strong.



I think that military play is even more essential against high difficulty AI than against human players. ED (Endless Difficulty) AI manages to expand at ~twice human rate. Wars fought between AI will leave a large map heavily controlled by a single faction. Economic victory by AI is unlikely due to the combinations of techs required, but with the research bonus EDAI gets, science victories can be achieved without too much specialized tech.



Here are my tips against EDAI:



You will not make a single Legendary Building or achieve a single Legendary Deed. So stop trying.

Peace is powerful. Diplomat's Manse gives you nearly perfect protection against fighting a war on multiple fronts-- or even on a single front, if that's how you want to roll. It also lets you identify the capacities in which an AI threatens by identifying which random techs they've picked up.

Quest and wonder victories are easier. Having AI around with massive quantities of t4 resources is almost like having massive quantities yourself. Units and heroes can level much more quickly when fighting the AI's numerous level 8 units than they would otherwise be able to.



On military:



Number of AI units starts high but rises slowly. Massive production bonuses mean that early AI have a tremendous number of units. A dragging economy secondary to schizophrenic, RNG-guided choices prevents their military size from rising linearly.

AI unit levels start low but rise quickly. At the beginning of the game, every factions' units are level 1. At the end of the game, the AI's units might be level 10. If you wait until the end of the game to create a military, or rely on garrisons to level your military, your military will be little more than a speedbump to the superior AI military.

Strong combinations of equipment are unlikely on AI units. Good equipment requires the unlikely conjunction of extractor tech, weapon tech, and armor tech. Good items like titanium rings are likely to be replaced with higher tier (but inferior) accessories. Check via Diplomanse to see which AI (if any) have lucked out on strong tech. If they have, wait a tier and check again.

Garrisons will all, always, be full of units with comparable strength to the AI's roaming armies. You've really go to draw them out to participate in battles without fortification. Thankfully, this is easy. I don't believe I've ever had to siege an AI-controlled Cultist capital. Attack the converted village next door and they all rush out to defend.

Maybe this thread should be renamed: Ways the the AI needs to be fixed. :P



But good tips guys.



On military/battles:



-Use Coast Lines, Cliffs, Choke points, etc to your advantage. The AI does not handle any of these well.

-Have wounded units run around like crazy. The AI will follow them. Or, have wounded unit on one side of map and other units on other side.

-You can generally get a better result on a wide open plains battlefield by splitting units up. AI will doggedly send units after 1 unit at a time, so you can pick off AI from distance with ranged units.

-I always set units to "Stand/Hold Ground", and manually input movements. Having the AI move for you is asking for dead units.

-Focus on high damage causing units first regardless of what the AI wants you to do.

Can you explain how you manually input movement?

I can't figure out how to say move here then fire at them.



I only seem to be able to move or fire.

Though if I select a target too far away the unit will choose to move and fire.. but I can't predict where... or even see if the target is out of range.

Click on location, ctrl-click on target.

natev wrote:
I don't see how RC could win an econ victory faster than BL though.

RC gets some incredibly powerful trading tech from their questline, and trade routes backed up by an RC hero have a tremendous bonus.







Trade route income is displayed incorrectly, leading people to believe it's a lot less powerful than it is. Nominally, that city is only receiving 7210 from trade routes (2403 without Grassilk), however, demolishing the Right of Way improvement causes its income to drop to 1586 - meaning that city is actually getting 16980 from trade routes and their attendant bonuses.



Removing the level 14 Siryi Alastra starting-hero that I had governing the city causes its income to drop to 3210, even before the lack of outgoing traderoutes to necrophage conquered cities get removed at end of turn.



Market Ban is also more effective than Close Borders at extorting resources out of the Necrophages.



I'll grant that BL can be almost as good if they have an RC hero in a few key cities, though missing out on Trader's Tents and Wells of Dust hurts a lot. And against Endless AI, though, it's hard to get either of those techs... so you may actually be right.

What turn is that screenshot from?

That particular one is from turn 124. Rather late on, but I screwed up my start and was stuck on two cities in that game which slowed progress. In other games, I can get a city like that by turn 95-ish if I'm not fighting any wars and have 3-4 cities. (Fast speed, of course)



I think I could get it faster with a more optimized build. I haven't actually tried it since reading the early game guide thread - and I think I've been focusing way too much on Food.



I'll do more concrete testing tomorrow so that I can speak from data and not speculation.

I don't know a lot about RC, so I'd love to find out exactly how fast they can pull off an econ win.



When I tested econ victory, I did it in 89 fast turns with vanilla BL. That was on a huge map-- the dust needed scales with map size. No Guardians content, although none of that is really achievable vs EDAI anyways (well, dust transmuter is nice I guess). I remember it being pretty tedious That was also a very wide empire. I think you'd find that you'd do better with more than 3-4 cities. If you can achieve turn 95 econ victories with 3 cities, you should probably be able to beat 89 with more. At the late part of the game where you collect all your dust, managing approval with boroughs and luxuries isn't too difficult, especially when you get the AI to do all the gathering for you.



I think that BL tend to be a little stronger at econ just because they can reinvest every bit of dust they earn into their economy. Late game RC run out of economy-improving things to buy, while BL just buy more pop and more boroughs. Plus, you can get some glassteel with a market ban removal, but you can get even more with a truce

I keep wondering how worth it is to bother building as many boroughs as I can. I'm finding myself saying screw it and saving production + raking in happy/fervent bonuses that comes with few districts. I build as few as necessary to reach nearby high value anomalies and maybe a dense lake/river area since those give amazing yields with the right buildings(I actually think deserts are the WORST spots for dust yields).



It also helps to keep cities small in case I find myself in position to build a legendary building. It's a lot easier to level it up in a small city than a larger one.

An entire guide could be written on how to exploit AI diplomacy deals. The biggest I've noticed is that they severely overvalue dust while severely undervaluing resources. 800 dust for 100 of the current highest level strategic resource? Yes, please!

Update: I got an RC city up to that income level at turn 84, vs. Impossible AI. I made sure one of them was Cult so there would be enough room for me to grow, and nabbed 5 cities before getting boxed in.



I also discovered that it's possible for a map to be generated entirely without Grassilk, which really clobbered my economy. I had 25 grassilk from Quests, and had to use Salting the Earth on one of my cities to bring myself low enough to use it, but that five-turn boost was enough for an economic victory on turn 88. (Large map)



Advantages to RC:

-Slightly faster in optimal circumstances (we just-about tied, when my game had neither Dustwater nor Grassilk)

-Can win on very few cities; never needs to go to war

-Can use market ban to extort resources from the necrophages.



Advantages to BL:

-Can go to war to get more space.

-Can go to war to get more strategic deposits.

-Can go to war to get more luxury deposits.

-Can go to war to extort resources/tech from the necrophages.

The difference between large and huge is 350k dust vs 450k dust. Grassilk or dustwater would probably make up the difference. Good to know.