Disclaimer: 100% biased thread so don't feel bad if you don't see a tech here I missed. This is also not a priority list by any means. It also doesn't mean YOU HAVE to do these techs. But sometimes you should if you feel its gonna be a long one.
Let's start off with basics.
1) Berbers Kasbah tech. Upon clicking imperial, if your intent is trebuchet warfare or massing your UU or allies UU faster. Please get this tech the second you click the imperial age button. This tech pays for itself extremely fast and is often neglected. For 250f 250g, there isn't any reason to skip it.
2) Tigui. Although malians lack bracer (thanks matt salsa) and this tech semi diminishes throughout the game. It is still a decent raiding deterrent for weaker units. Not so much paladins or champions or siege rams but moreso for Hussar, Halbs, etc. It's another cheap tech often ignored and is worth it every now and then.
3) Strongholds. Yes although celts lack of bracer sucks. I found this meme of a tech pretty underrated. It can compete vs ungarrisoned Teuton/Korean Guard Towers and it's DPS is comparible to Yeomen Keeps. Not only that, this tech actually does more DPS than Persians Boiling Oil (slightly less to rams but more to other units). Yasama Keeps remain the highest in DPS still though.
4) Arrowslits. Despite the nerf and move to Imperial. This is still a worth while tech if you have a bunch of guard towers around. It makes your already annoying presence even more annoying. In terms of tower upgrade priority this should be done before Keep upgrade. A bit like you do Parthian Tactics before HCA.
5) Guard Tower/Arrowslits and Keep. If you're a tower civ other than Koreans and you've been going towers. Well you should do these upgrades. WK guard towers seriously hurt mangonels and secondary arrows now do more damage than before. In some situations BBT is banned. So this is next best.
6) Guilds (but in early imperial). Usually gold is not an issue at this stage of the game but in a 1v1 it can be. Especially if you're a civ like Turks who rely on gold. Best to have a backup option than no option at all. Only do this if you can afford to though so. If you have an advantage dont lose it.
7) Great Wall. Underrated Chinese tech. Very good vs defending BF pushes and offensive BBT play. Theres a reason MbL loves towers and especially BBT.
8) Inquisition. If you hate monk wars or have a slow reaction time. This tech is for you. Being able to convert 50% faster on average is no laughing matter. Pair it with 65hp missionaries and Conqs for ultimate fantasy plays.
9) Paper Money. Although good in TG. In 1v1 it's still worth it despite it's one time use. I still think it's weird a tech like this costs gold to begin with but hey ho I'm not Cysion.
10) Chivalry. I didnt want to think I had to add this tech here since it is done on tournaments. If you're wondering why Franks are consistently #1 on Arabia even after Feudal. This is it. Causal games this is not done and it really is worth 1 castle investment (franks pay 488s remember) for 40% faster working stable. Paladin is quite a lengthy research time and this cuts the time down considerably.
11) Sultans. Indians kinda need all the gold they can get. Worth it in both 1v1 and TG. A must grab at least in imperial age.
12) Nomads. While on the surface this appears to be useless. Imagine this. You are 200 pop but enemy units are breaking down your buildings and you are suddenly 200/160 pop or your trade line is inefficient coz your houses are in the fricking way. Well good news. Do nomads and all your problems are gone. Good right? Just a shame it's never done heh.
13) Druzhina even if you are only going trash units. Do you guys wanna know an amazing secret that nobody but 50 players in the world know? Halberdiers cost effectively counter elite eagle warriors (maybe not quite mayan ones). I'm not joking. Sure the price tag is 1200f 500g and 300f 600g and 210f 90g but this is a small price to pay vs the guy getting all his eagle upgrades. Backed with cheap siege this is often neglected. Always do druzhina. No excuses. Each post imp slavic farmer gets 27f/min so 1200f as a tech is nothing. You can lose 6 vills in feudal with slavs and still enter castle age healthily for some reason. Dont let the price of this tech fool you. Also free tracking is a god tier blessing here.
14) Ironclad. Actually a good tech. Teutons is often mocked for being a slow civ but this gives them some fighting power. people forget teutons get good siege and acceptable monks. Vs certain units FU teuton siege even surpass celts FU siege barring their ram line.
15) Hoardings. If you have a safe castle at home but one forward fighting vs trebs. Consider doing this. Especially if you're say the byzantines. That castle survives so many extra hits it's insane. Coupled with masonry and architecture for other civs. You have quite a defence there. Situational but for 400w 400f it ain't bad fam.
Let's start off with basics.
1) Berbers Kasbah tech. Upon clicking imperial, if your intent is trebuchet warfare or massing your UU or allies UU faster. Please get this tech the second you click the imperial age button. This tech pays for itself extremely fast and is often neglected. For 250f 250g, there isn't any reason to skip it.
2) Tigui. Although malians lack bracer (thanks matt salsa) and this tech semi diminishes throughout the game. It is still a decent raiding deterrent for weaker units. Not so much paladins or champions or siege rams but moreso for Hussar, Halbs, etc. It's another cheap tech often ignored and is worth it every now and then.
3) Strongholds. Yes although celts lack of bracer sucks. I found this meme of a tech pretty underrated. It can compete vs ungarrisoned Teuton/Korean Guard Towers and it's DPS is comparible to Yeomen Keeps. Not only that, this tech actually does more DPS than Persians Boiling Oil (slightly less to rams but more to other units). Yasama Keeps remain the highest in DPS still though.
4) Arrowslits. Despite the nerf and move to Imperial. This is still a worth while tech if you have a bunch of guard towers around. It makes your already annoying presence even more annoying. In terms of tower upgrade priority this should be done before Keep upgrade. A bit like you do Parthian Tactics before HCA.
5) Guard Tower/Arrowslits and Keep. If you're a tower civ other than Koreans and you've been going towers. Well you should do these upgrades. WK guard towers seriously hurt mangonels and secondary arrows now do more damage than before. In some situations BBT is banned. So this is next best.
6) Guilds (but in early imperial). Usually gold is not an issue at this stage of the game but in a 1v1 it can be. Especially if you're a civ like Turks who rely on gold. Best to have a backup option than no option at all. Only do this if you can afford to though so. If you have an advantage dont lose it.
7) Great Wall. Underrated Chinese tech. Very good vs defending BF pushes and offensive BBT play. Theres a reason MbL loves towers and especially BBT.
8) Inquisition. If you hate monk wars or have a slow reaction time. This tech is for you. Being able to convert 50% faster on average is no laughing matter. Pair it with 65hp missionaries and Conqs for ultimate fantasy plays.
9) Paper Money. Although good in TG. In 1v1 it's still worth it despite it's one time use. I still think it's weird a tech like this costs gold to begin with but hey ho I'm not Cysion.
10) Chivalry. I didnt want to think I had to add this tech here since it is done on tournaments. If you're wondering why Franks are consistently #1 on Arabia even after Feudal. This is it. Causal games this is not done and it really is worth 1 castle investment (franks pay 488s remember) for 40% faster working stable. Paladin is quite a lengthy research time and this cuts the time down considerably.
11) Sultans. Indians kinda need all the gold they can get. Worth it in both 1v1 and TG. A must grab at least in imperial age.
12) Nomads. While on the surface this appears to be useless. Imagine this. You are 200 pop but enemy units are breaking down your buildings and you are suddenly 200/160 pop or your trade line is inefficient coz your houses are in the fricking way. Well good news. Do nomads and all your problems are gone. Good right? Just a shame it's never done heh.
13) Druzhina even if you are only going trash units. Do you guys wanna know an amazing secret that nobody but 50 players in the world know? Halberdiers cost effectively counter elite eagle warriors (maybe not quite mayan ones). I'm not joking. Sure the price tag is 1200f 500g and 300f 600g and 210f 90g but this is a small price to pay vs the guy getting all his eagle upgrades. Backed with cheap siege this is often neglected. Always do druzhina. No excuses. Each post imp slavic farmer gets 27f/min so 1200f as a tech is nothing. You can lose 6 vills in feudal with slavs and still enter castle age healthily for some reason. Dont let the price of this tech fool you. Also free tracking is a god tier blessing here.
14) Ironclad. Actually a good tech. Teutons is often mocked for being a slow civ but this gives them some fighting power. people forget teutons get good siege and acceptable monks. Vs certain units FU teuton siege even surpass celts FU siege barring their ram line.
15) Hoardings. If you have a safe castle at home but one forward fighting vs trebs. Consider doing this. Especially if you're say the byzantines. That castle survives so many extra hits it's insane. Coupled with masonry and architecture for other civs. You have quite a defence there. Situational but for 400w 400f it ain't bad fam.