Civ V: Research Catch-Ups

I was annoyed at the last Civ V video I watched because the guy playing didn't talk at all to explain anything so I went searching for someone who does. Yoruus is a pretty cool dude who clearly doesn't speak English as his first language (he sometimes has to stop and think to find the right word) but he does a really good job of explaining what he's thinking. And he even uses the crazy opening I used to use way back when I first started playing where you open up both tradition and liberty to get the early culture bonuses! The more I think about it the more I actually like it, since the tradition opener pretty much pays for itself over the whole game and gives you faster border expansions. I really wish I had it in my Dutch multiplayer game since my cities refuse to border expand any of the hills near them! How am I supposed to stop growing the cities and work all the hammers without hills? I've mostly been watching his 2 player real time games so there's actually not much to learn from them but they're entertaining and that's good enough for me!

Anyway, he has some videos tagged as being important or something and they talk about a science bug in the game that can essentially grant all of the techs one turn at a time starting at the middle of the game. His test run took a civ that almost had architecture and was able to learn the entire tree except lasers, stealth, and future tech. You get knights and pikemen along the way so it's not even a super vulnerable strategy! I decided I wanted to know more about it, but rather than try to find a post about it on the internet I decided to rig up a test game of my own to see if I could figure out what was going on.

The crux of the matter has to deal with a catch-up mechanic I didn't even know existed in the game. Basically the idea is techs get cheaper the more other civs you know that have learned the tech. It makes some amount of sense. It's easier for me to figure out a book when I see that Dave has a big stack of them over there. I wrote down a bunch of numbers from my test game and it looks like there's not an exact discount but it's in the area of 6.5% cheaper per player. Or maybe it's just rounding screwing things up? I learned that the game only displays whole numbers in the tech tree but it definitely keeps track of the decimal points so it may well actually be 6.5% per player. It may also vary based on number of players or difficulty or game speed or map size. The precise amount doesn't really matter though, the important thing to know is that techs get cheaper as other people learn them and that you need to actually meet the other civs before you get the discount.

I was lamenting on Facebook that I didn't see how I could keep up with Dave in tech since he's making approximately three times as many beakers as I am. I still need to build a national college and universities and such to close the gap but it felt like I was going to be stuck way behind for the whole game. But if it turns out I only have to pay 87% of the cost of the techs that he had to pay I don't need to pass him in beakers to catch up. I just need to get close and the discounts should be a boost. There's also apparently a premium for researching the first medieval era tech where that person needs to pay like 4% more. Couple that with the other catch-up mechanic (spying) and things only look bad, not impossible. That is, if I'd met Dave. As things currently stand I couldn't spy on him even if we had spies and I'm stuck paying full price for my techs because I'm stuck on an island on my own. My worry is the first time I meet Dave it'll be an entire army landing on my little island and starting to catch-up at that point won't be worth anything. Of course he could just stay away and deny the discounts as long as possible while building up a powerful position to win the game any of the other ways. Bleh.

Anyway... Catching up is fine and all but what about that bug? It turns out the game is set up such that you can only learn one tech at the start of each turn. You can learn more than one in a turn if you learn free techs or earn science in the middle of your turn (like by popping a great scientist) but otherwise it just carries any excess science forward to the next turn. Even if that excess science would be enough to learn multiple techs at once. Like if you saved up a bunch of great scientists and used them all in one turn, for example...

Here's the state of affairs in my test game after I'd played around a bit with abusing the bug. You'll notice I'm working on learning sailing which costs a mere 36 science. I have 4159 science sitting around waiting to be spent. On this turn I legitimately earned 87 science from my city. So if everything was working properly I'd expect to add 87 to my 4159 to get 4246 and then pay out 36 science to learn sailing. I should be left with 4210 or so, with weird rounding maybe shifting things by a couple. Instead...

That's not 4210! That's 292 bigger than it should be! Which is in the neighbourhood of the ~6.5% discount for someone else knowing the tech. I made notes of every tech I picked up during this overflow streak and the pattern holds up. Tech known by 3 other civs gave a boost of around 19% to the science on hand. At least when the cost of the tech was small compared to the overflow. There was still a gain even when I was working on techs that cost over a thousand each but it slowed down and petered out. Part of that problem is I was getting techs known by only one other civ, not three. And I didn't manipulate the start very well I don't think. I certainly only got almost to the modern era before I ran out of science, but it was still a big gain.

So how did I set up my test? I made a hotseat game with 4 civs. It was a quick game. I wandered them around until they all met each other. Then I settled down and set them down different paths. One civ was going to be a scumbag cheater. His goal was to get all the research buildings in order to have as big a burst as possible when I used great scientists, and then was to pick up said great scientists. One civ just went down the bottom of the tree, taking mining and going as far as they could. The third civ followed the second civ but first it detoured up to get a national college. The last civ was designed to research all the things so it beelined straight to universities and also picked up the great library along the way. All of the civs built a worker and then tried to get as high a population as possible to max out the science gain.

I totalled up a few numbers for each civ at various points of the game. My bug ran out on turn 147 after settling so that's going to be the end point. I'm also going to look at the numbers after 50 and 100 turns. The numbers are total beakers earned (by science per turn or by burning a great scientist), total base value of techs learned, and 'free' beakers earned either by a catch-up mechanic, the bug, or rounding issues.

50 turns	Babylon	Austria	Assyria	Russia
Science Accumulated	518	350	527	720
Total Tech Value	568	364	585	868
Bonus Beakers	50	14	58	148

100	Babylon	Austria	Assyria	Russia
Science Accumulated	2147	948	2357	5296
Total Tech Value	2392	999	2441	6338
Bonus Beakers	245	51	84	1042

147	Babylon	Austria	Assyria	Russia
Science Accumulated	7159	1778	4560	15572
Total Tech Value	17256	2023	4638	16753
Bonus Beakers	10097	245	78	1181

Now, the city spots weren't all equivalent. Russia got to settle near Lake Victoria which was huge for early pop growth. They were also beside a mountain. One interesting thing is despite growing at the same rate and being later in turn order Assyria actually got writing a turn before Babylon did. Because they had to pay 2 less science for pottery as a result of Babylon learning it first. Russia's early beaker bonus was almost entirely the free tech out of the great library which I didn't count as science accumulated. They also accumulated significantly more science than the other players thanks to the +3 from the great library. They were slower to national college because the other two civs got to build the cheaper library and then start in on it right away. But once they got them both up they were making double what the other science civs were making. And more than 5 times as much as the poor mining civ! The university really put things over the top with the science per turn sitting at 36-13-40-145 at turn 90.

I didn't do a good job abusing the bug but even still look at the end result! Babylon ended up with more tech value learned on turn 147 than Russia did despite Russia actually being such a dominating science force. Some of the 10000 free science was the legitimate catch-up mechanic but the vast majority of it was the bug coming home. And at the end, after rush buying the public school for Babylon, the science per turn ended up at 182-20-59-272. Babylon still had the oxford university to build, too, which was where 550 of Russia's bonus came from.

I actually ended up abusing the bug a little bit with Russia without meaning to. They probably only got 300 or 400 free science out of it, but when you're researching techs that cost 80 or 100 that's a pretty huge boost. (Also, Austria only got 2023 total value in techs all game... So 300 free science is really big relative to them!) They didn't even have to pop a great scientist or anything... They just plowed straight up to universities without getting any of the side techs. They researched masonry (which cost 33 beakers) while they were generating 119 per turn! And that was with only 2 civs knowing masonry... If Babylon wasn't also being cheesy and had also picked it up the cost would have been lower and the carry-over multiplier would have been higher.

There's one thing I didn't do in my test, and that's grab the 'scholars in residence' diplomatic boost. If that boost gets voted in the cost of all techs is lowered by 20% if any other civ knows it. Given what seems to be the case with the carry-over multiplier having this in play would stack up the science lying around by an absurd amount.

I also suspect you could set up the bug even when you don't have a lot of low cost techs lying around. You could, for example, research most of a tech and then switch to something else right before it finished. This should manufacture a fake low cost tech. Prep up several of these and then pop your great scientist and go to town. I suspect this is what the guy was doing in the first game I watched since he switched off of a tech and I didn't understand why but he eventually popped several great scientist at the same time to burst his way to artillery. I thought maybe he did that as a surprise move to jump up in the literacy number but he could have also done it to steal some extra beakers to get there a little faster.


Ok, so this bug exists... What should be done about it? There are people who would say anything in the game is fair to use. I feel like this bug is outside the realm of what's acceptable but I hate enforcing outside rules on a game. Even my civ that was trying to play fair ended up using the bug incidentally! Anyone that rushes national college into university while mostly ignoring the other junk is going to get extra free science for doing so. I actually wouldn't be surprised to find out that Dave unintentionally got some science out of the bug in our faster asynch game. He was making more than 50 beakers per turn before I was even close to researching writing. The writing tier of techs cost 36 with someone knowing them, the first tier only costs 23! So if he'd met Robb by that point in time and if he researched any early tech that Robb knew (mining/masonry/bronze working?) he could have triggered the bug. It probably wouldn't be for very much, but when I'm only making 11 per turn him getting 8 for free is a big deal.

How could you even fix it? You could research all the 'cheap' stuff before you power up that many beakers? You could only select a 'cheap' tech after barely finishing a previous tech so you're not carrying over more science than the cheap tech costs. Or you could just accept that sometimes it will happen.

The big thing is to not pop a great scientist for a huge amount of science and then research a cheap tech. Pop the scientist to get an expensive tech, and use it early on in the tech?

Some people have suggested banning great scientists entirely. Use them just for the improvement, never for the one shot. Which sucks, but if the alternative is making them absurdly powerful? I donno. Also you could ban scholars in residence since that's what really gives you the huge overflows. But even without it I was able to more than double my science!

Or you could just play with it as a potential strategy. I don't know how a real game would actually go if I wasn't allowed to research anything from mining forward and if I was forced to generate 3 great people without using them for 125 turns. I feel like someone should have killed me by then...

But then I think about my Dutch game... I'd need to take sailing in order to go meet up with Dave but it would have been a strong strategy to build up just science and ignore the bottom half of the tech tree. Meet Dave and then more than double my science? Seems strong. As it is I have several techs that will only take 3 turns to finish and I don't have universities yet. Even without the bug existing it's definitely right to rush to universities and eventually I will meet Dave. All those cheap techs may well become cheaper than one turn. I could probably alternate picking them up to not get extra science, but if I don't want those techs yet it seems bad for me.

Anyone have any thoughts?