No coastals, but mountain cities: observatories before or after schools?

The question concerns multiplayer games since i dont play singleplayer anymore, but i think that shouldnt make a difference.

Especially without any coastal but with mountain cities i am often unsure if a detour on the tech tree to observatories is worth the delay of other important stuff. Usually i try to steal my way along the top of the tech tree in these situations which often leads to observatories after schools.

Under which circumstances should i make observatories top priority? How is the science bonus calculated? Does it only refer to the current science buildings in the city, or will it still be put on top after additional buildings?

Observatory is a straight 50% science bonus on base beaker production, like National College's 50%, University's 33%, and Labs' 50% -- all of which are additive (i.e., NC, plus observatory, plus university, plus lab is +183% beakers). As base beaker production rises (e.g., additional population growth (which are boosted by library and public schools before multipliers) and additional specialists, the value of the multipliers also rise.

With no coastal cities, I usually go for Scientific Theory before cleaning up the Sailing line -- the additional specialist in the school helps generate more GSs and the +50% science per pop is its own bonus. Plus you really don't NEED the observatory bonus until you are working all specialists and trade posts for the 8 turns after building and filling labs, preparatory for your massive end-game GS bulb-fest. Just my opinion - YMMV.

Considering that multipliers are additive, and Universities already give +33% multiplier (50% with Free Thought) an Observatory will in reality give a bit more than a 33% increase to the science in that city (less with the NC). That's similar to what you get from a school, going from 1.5 per pop to 2 per pop. There's also the fact that they've got a scientist slot; also, it depends on how many cities you have next to a mountain.

Also, @Browd, wouldn't it be a good idea to tech Observatories soon after ST? After all, they give as much science as a lab, minus the specialist slot, but are much easier to research, and will probably get you to labs at the same time or before you would without them.

I think a meaningful factor in whether to detour to tech to Astronomy before Plastics is your number of observatory-eligible cities.

If (as I find in most of my games) I have maybe 1 or 2 observatory cities in an empire of 5-8 cities (including conquered cities--I always seem to have some), being able to bang out labs in all cities would trump observatories in a city or two (particularly if one of more of the observatory cities was still relatively small).

If, on the other hand, I'm playing, e.g., Incas, where every city is nestled next to a mountain and growing like crazy with terrace farms, I would likely beeline observatories (maybe even before Scientific Theory).

At the core, of course, this is a math problem involving raw beakers and opportunity cost. As ever, it's decently complex, so as to not have an easy answer amidst a lot of changing variables.

In short, an Observatory is most powerful on large cities with raw beakers. The +50% isn't that impressive without the raw beakers, and generally that means your capital (where you've presumably already planted an academy or two). Hence, unless you've got a mountain capital, the boost to your science by an observatory varies dramatically. In that respect, it's probably best to wait, particularly if you're going to follow the traditional play of Oxfording into Radio and Ideologies ASAP. In that case, making a beeline to Scientific Theory and then timing Electricity and Oxford on the same turn is something where every turn helps.

Without a real reason (i.e. Capital with a Mountain), I wouldn't deviate from my push to Electricity unless I did the math and somehow I could hard build Observatories (you wouldn't buy them, presumably given the better use of gold elsewhere) to the point where it didn't slow down my path.

Basic point: without a mountain capital, it's probably not worth it. You can go for it after Electricity. Particularly in MP where you really don't want to miss out on the Early Adapter Ideology Bonus. With no need for a navy, I'd go for a lot of other techs before Observatories unless the Mountain Capital.

BNW actually introduced a new reason not to let the sailing line languish to long for a non coastal empire.
Compass adds a trade route, so you may want that tech just for the new (land) trade route. If you already have that then Astronomy is much closer than otherwise.

Observatories are actually pretty hard to build early in cities other than the capital, as your build orders are so clogged up in mid game. If you've got a mountain capital, clearly theres a lot of incentive to get an early observatory since that is normally your highest population city as well. A jungle/mountain capital would be nearly mandatory.

depends on the capital. that is by far the most important observatory since its where you have by far the highest base rate (largest pop, academies, NC, etc.). If your capital has a mountain then observatory before school for sure.

Depend of situation. Astro is away from military techs. Make sure to have the whole situation under hands.

If no threats, i strongly recommend to "beeline" Astro if your capital can build one. Can be good if 2 or more non capital cities can build that too.

Btw, i usually beeline workshops unless i have bazillion of rivers so i can build all the costly stuff faster. Workshops beeline is probably the most underrated approach under mp. Use this approach to make this observatories "beeline" more appealing.

So the response is before public schools(without a doubt).

Map could make a big difference too. You don't need coastal cities to want to explore the oceans. On Pangaea, not a big deal. On Terra, yeah, big deal. If there are many offshore CS's or two large landmasses separated by coast, you probably want to be able to get over that, which at least means observatories are closer.

I would just echo that it's quite variable. If you have one city on a wide start next to a mountain, likely not worth it. If you have 4 huge Incan cities all next to mountains and feeding food caravans into each other, it probably is worth it.

It's also worth keeping in mind that even without Sailing (which is a cheap tech for a trade route anyway), Astronomy is only 4 techs from Education, 2 of them super cheap. Scientific Theory is 6, even if you start from Printing Press, though many of those techs are likely to be more useful for a landlocked civ. Looking at beakers only, Astronomy is likely less effective in most cases, but has a significantly lower cost of actually getting there. The other things, your cities, their beaker output, your situation, your victory condition, etc. all complicate things far too much to get any solid answer.