Late game: Smart aliens and advanced evolution

[EditorRUS]

Currently the only real threat you can see in late game is behemoths, which are pretty stupid to be honest. I mean, they have the very same behavior of regular biters and the only difference is health and resistances.
I suggest replacing behemoths with "smart biters" and "smart spitters".

Smart aliens have a different AI which makes them avoid "dangerous zones" and also evolve to resist certain damage types which are used to kill them.

I am not exactly sure what path finding algorithm is used in Factorio, but I think it is A* because, well, there is plenty of open space and very rarely do things block your movement. A* is the most efficient here. I will try to explain how to define a "dangerous zone" on the assumption that the algorithm is, in fact, A*.

Each chunk on the map should have an associated value that shows how "dangerous" this zone is. This value decays very slowly if it's high and very fast if it's low. This value should be increased each time a biter or a spitter is killed in this chunk. When A* comes into play to find new paths, this value should be the third additive in path cost evaluation. Basically if many aliens were killed in this particular chunk, then smart aliens will avoid crossing this chunk and try to find alternative ways to the source of the pollution. Regular biters and spitters don't follow this rule however and will run into mines and turrets. This will eventually make smart biters and spitters "find" weak spots in the defense, avoid land mines and protected areas and wreck the hell out of the base. Smart biters and spitters will also try destroying any unprotected player-made building even if does not produce pollution. This will make late game a whole lot more fun than it is now.

Also, smart aliens should increase their resistances to some particular damage types. Each time a regular alien is killed, you need to get the damage type of the thing that killed this alien and slightly increase the resistance to this damage type for all future smart aliens. This resistance growth should decay as more and more resistance is being set to avoid 100% laser-resistant aliens. Also, if some different damage type was used to kill an alien, then other resistances will decay.

So if you were to use, say, lasers to kill lots of aliens and they finally get 50% resistance to laser type damage, then if you start using gun turrets to kill the aliens, this laser resistance will slowly drop back to 0%, but resistance to gunfire will grow instead.

UPD: Apparently there is a mod for that ™, but I strongly believe this should be a core mechanic. Late game enemies should not only be strong, but also smart enough to avoid being killed to still pose a threat. While the player can still surround his entire base with turrets, it should become prohibitively difficult to do so as you expand your base. The player must adapt to enemies becoming more smart to avoid a situation where your factory is always protected and nothing can beat it no matter how hard they try. Simply increasing HP and damage directly or indirectly is not fun if the enemies themselves are very basic.
Link to the mod: https://mods.factorio.com/mods/Veden/Rampant

UPD: As a matter of fact I should also say that this might be an indirect countermeasure for turret creep. If lots of enemies get killed by turrets somewhere, they will instead try to bring down unprotected poles that power up laser turrets instead of stupidly trying to attack the player. This might be extremely fun for the player whose turrets stop working in the middle of firefight.

[Veden]

https://mods.factorio.com/mods/Veden/Rampant

I use potential fields, but achieve the same effect.

The resistance stuff I haven't worked on yet, but I have plans for and have a half finished unreleased update for making adaptive type aliens.

[EditorRUS]

Oh great, I'll check this mod out. Noted and updated OP post.

[ssilk]

See also viewtopic.php?f=80&t=3440 What do biters do in their spare time? (Pheromone pathfind)