AI still researches Future Tech even when it loses tech
The fact that one can even research Future Techs when there's unknown techs in the actual tree is most likely a bug in itself. You can't start researching Future Techs before you know the entire tree, why should you be able to continue doing it (even starting new Future Techs) if you've lost techs?
Savegame from the game where this is happening would probably help, if you can attach one.
Reply To cazfi
Savegame from the game where this is happening would probably help, if you can attach one.
I uploaded a save file (I don't recall the exact turn it started, but at this point in the game the AI is losing tech due to a negative balance) in google doc (anyone with link can download the save file) https://drive.google.com/file/d/1drOk6zvMGELtqe67dnJu3FKfa0WP5_RY/view?usp=sharing
To be clear, future tech is unlocked only once you complete the tech tree once, however, both I as a player and the AI can both continue researching future tech even when we lose a tech (only the AI never switches off the tech tree)
I downloaded the savegame, and attached it to this ticket, so we have a copy even if you remove it from google drive.
Seems to have been saved by freeciv version 2.6.5, with civ2civ3 ruleset in use.
Reply To cazfi
I downloaded the savegame, and attached it to this ticket, so we have a copy even if you remove it from google drive. Seems to have been saved by freeciv version 2.6.5, with civ2civ3 ruleset in use.
Also:
last_turn_change_time=228256
So reproducing things with this savegame might not be something to run while you grab a coffee. OTOH it makes this an interesting savegame, e.g., for testing performance differences between freeciv branches.
Reply To cazfi
The fact that one can even research Future Techs when there's unknown techs in the actual tree is most likely a bug in itself.
I hoped that resolving that part would sort also everything else, as losing ability to select future techs would cause all of the behavior to revert to normal regular tech research one. Unfortunately it's not that simple. So now I've split that one part to a new ticket -> #44592.
Split also #44594, not necessarily a cause for any of this, but confusing debugging attempts.
Not sure if this is related to the core of the problem or not, and unfortunately, I no longer have a save game since the game saving format overrides older games with newer games, but it may be worth looking at Ticket #43847 if that wasn't already reviewed
More problems detected with the savegame split to a new ticket. "unused entry" -warnings -> #44809
With this savegame, part of the problem is also #45397 -> AI is not actively selecting what it research as it assumes that human team mate will.
Attached patch makes AI to switch from future tech research to regular tech research even mid-research when regular tech becomes available (#44592 already forced it, and human players alike, to select regular tech when starting new research)
I think this completes this ticket. Some spinoff tickets are still open.
Not sure if this is a bug or unintended programming, but once the AI completes the tech tree once and starts getting into future tech, if it loses tech due to an insufficient research point balance (which classic and most rulesets have), the AI won't switch the tech to unlock whatever tech was lost and the game allows.
In the game I played for over 500 turns, the AI in question (set to hard difficulty, using the civ23 ruleset, it completed the full tech tree around turn 480 and never switched tech despite losing over a dozen techs (it went as far back as losing communism and the AI was still researching future tech each and every turn until the game ended around turn 550). The game was configured to teams, this AI was part of the player's team and despite not having the tech, the AI didn't ask for tech via diplomacy as it occasionally does when configured to be in teams. The game settings had a tech penalty for changing tech, but only 50% instead of the default percentage when changing tech mid research.
The recommendation is unless the ruleset has perks for future tech (to my knowledge, classic and most rulesets don't use future tech for anything), if the AI is researching future tech, check the tech tree to see if there are any missing tech and change to that. Otherwise, this exploit could be used to cripple an advanced AI civilization into easy submission because it suddenly loses all the keystone technologies to make it a viable challenger to the other players