This has been mentioned in other threads that with the 3.19 patch vassals will always trade tech, but it deserves its own thread given the strategy implications in single player games.
Previously, you had to stay likable to ensure that you had a tech trading partner, especially if you wanted to research deep down a particular line on the tech tree. Now, you can research deep down the tech tree (for say military techs) with the reliable plan of running over a tech leader and then trading with them to catch up (even if they are furious with you).
I have been having particularly good luck on emperor level with slingshoting feudalism with the oracle. Run over an AI with your 5exp longbowmen and then trade monarchy and feudalism with your now vassal to get any techs that you might have missed. I've even had some success demanding a tech immediately after they vassalize (hey its not much of a risk trying because the arrogant demand penalty doesn't matter much with your vassals now). Rinse and repeat with other neighbors.
Thumbs up for the change. Previously, I resented having to kiss the butt of my vassals to ensure that they would trade tech with me. Even when I did, more often then not they would red out certain techs that I needed, e.g. if they had a monopoly and/or were building the wonder.
Previously, you had to stay likable to ensure that you had a tech trading partner, especially if you wanted to research deep down a particular line on the tech tree. Now, you can research deep down the tech tree (for say military techs) with the reliable plan of running over a tech leader and then trading with them to catch up (even if they are furious with you).
I have been having particularly good luck on emperor level with slingshoting feudalism with the oracle. Run over an AI with your 5exp longbowmen and then trade monarchy and feudalism with your now vassal to get any techs that you might have missed. I've even had some success demanding a tech immediately after they vassalize (hey its not much of a risk trying because the arrogant demand penalty doesn't matter much with your vassals now). Rinse and repeat with other neighbors.
Thumbs up for the change. Previously, I resented having to kiss the butt of my vassals to ensure that they would trade tech with me. Even when I did, more often then not they would red out certain techs that I needed, e.g. if they had a monopoly and/or were building the wonder.

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