Has there been a change to the Civ6 AI at the Immortal level? Is it suddenly impossible to beat it?

[mandrewa]

I switched to the Immortal level maybe two months ago. I've won a number of games at the Immortal level.

But a week ago, I lost a game which I thought I had won. Suddenly seemingly out of nowhere, an AI won a Science victory. And actually I thought that was kind of neat. I assumed it was my fault and that I hadn't been paying attention.

But this game, the one I'm playing now, I have been checking every now and then on all the possible victories.

And thirty turns ago it seemed like I had it in the bag. I'm just 20 turns from a Diplomatic Victory now and I'm about that or maybe less from a Religious Victory. And no other player was seemingly anywhere near to any other sort of victory.

But seven turns ago I noticed that one of AI players was building tourists at an astonishing rate.

This AI has gone from 182 visiting tourists to 418 visiting tourists in just seven turns.

Is this plausible? Is this something that others have noticed the AI doing?

Is this something that it's possible for a human player to do? I'm not asking for how to do it. I'm just asking are there ways to do this sort of thing?

So here's more context:

I'm on the 285th turn. The AI is going to win in about 2 turns. It's too late to change this, but I'm trying to understand what happened. It was in fact too late to change things when I noticed seven turns ago that the AI was adding tourists at an astonishing rate.

Rock bands don't play any role in this. The AI is trying to prevent me from converting its cities so that means there is no faith left over for rock bands.

And the AI has about seven cities that are large enough to be relevant to tourism.

I'm allied to this AI but it's a religious alliance.

There were two other AI players that had a similar cultural level to this AI player seven turns ago, but not now. Their tourist counts are rising at what I would consider a normal rate. That is pretty slowly.

 

[Oberinspektor Derrick]

Yes its possible to increase tourist count and science progress at a very rapid pace.
For tourism you can go from zero modifiers to high modifiers (such as open borders, trading, online communities, slotting cards, to hard tourism sources such as flight, placing multiple natural parks/seaside resorts, or spamming rock bands) and tremendously boost your tourism in a short time span.
Similarly with science victory, if you have the techs unlocked (or close to unlocking), you can go from 0 progress to finishing the space race in just a couple of dozen turns through through such means as buying a spaceport district, using great engineers, chopping or builder spam (through the royal society) to boost the space race projects very fast.

Its rare that the AI does it and you usually get some warning beforehand, but the AI might luck out once in a while and do actually sensible plays to catch up really fast.
The best way to guard against this is to check their general tech/civic progress, as that gives you a heads up of what their "potential" really is.
Though the AI might not use that potential, that potential is still there and some bad "AI choice RNG" can screw you over pretty fast.

Its not really a problem once you get good enough that you beat the AI consistently early though, as you can often finish SV/CV conditions while they are still fooling around in the industrial era and nowhere close to winning.

Edit:
Also check if you have monopolies toggled.
If someone gets a monopoly from luxuries they can boost their tourism tremendously hard with minimal effort.
Monopolies mode is broken for this exact reason.