i like the idea but it would make the game harder i think, tin was quite rare so this one could be one wich should be more traded

Well copper and iron ore are very proilific so i'd say that having these on almost every map wouldnt be very unrealistic, as Miketonamor said though, tin is are very different beast as it is very rare (one of the only accessible deposits in Europa was in Cornwall or Devon I think) so having tin only from traders would be very realistic

Flint is also quite common and stone age settelements would often be located where flint could be found so I think that only putting one type of ore on a map is maybe overly restrictive. I think that having two different types out of Iron, copper and flint and having to buy tin from a trader on every map (maybe exept one) would be a more realistic situation

@Lucius Very good points.

I am thinking to make the trader come much more often, like 10 times a year for instance. The only reason I haven't done this so far is I was afraid people will buy 10 tech/year and advance too quickly (which would be unrealistic), but now I realize it is quite hard to gather enough resources to buy even 1-2 tech/year. This should solve lack of various resources on the different maps/locations, as well as randomness of tech advancements; plus you can actually rely on trade. What do you guys say?

More trader sounds very good. buying tech is quite expensive, or takes a lot of ressources so i also don't think it will become to fast. i normally had around a tech a year( if there was one to buy) which sometimes eat in my clothing supply so i don't hink it will be to fast.

Added more traders (depending on region), in latest update. Let me know your opinion.

The more frequent traders were a splendid idea!

@The Great Badger: Thanks for the feedback. I was afraid to increase it, as you could rush through the ages faster, but overall seems definitely better.

FWIW - Copper and Tin are actually quite rare in most locations. This is why people from the middle east were trading with what's modern England for tin.

Iron is bloody everywhere, though. The problem with iron is that by itself it's fairly suck - bronze is superior in most regards.

So... copper and tin should be a struggle. Iron was actually adopted because it's 'good enough', cheap, and plentiful.

@Itharus: Very good point. From what you, and Lucius Junius Aemilianus before you, have said, I looked up Wikipedia and from here it is quite conclusive that almost all settlements only imported tin:
https://en.wikipedia.org/wiki/Tin_sources_and_trade_in_ancient_times
"Europe has very few sources of tin. Therefore, throughout ancient times it was imported long distances from the known tin mining districts of antiquity. These were the Erzgebirge[..], the Iberian Peninsula, Brittany [..], and [..] southwestern Britain [..] several smaller sources of tin in the Balkans[..] and another minor source of tin is known to exist at Monte Valerio in Tuscany[..]. Even at that time, the Etruscans themselves had to import additional tin"

I did not find how common or rare is copper though. Can you guys help me out with links (and optionally citations)? so I can make new version with no tin and with/without copper.

Alpine meadow definetly could use more regular rocks....

Googled around & this webpage talks a bit about copper: https://www.worldhistory.org/copper/

Small quantities of copper would've been found everywhere, but it was only abundant in places such as Cyprus, the Levante or Athens. "less important copper deposits, were exploited in England, Wales, France, Italy (especially Elba, Sardinia, and parts of Etruria), Spain, and Mauritania."

(note: I think the webpage may mean ancient Mauretania which was around the north-western Maghreb, not the modern postcolonial country of Mauretania)

@Argacyan: Thanks a lot for the info and link, I'll take a look.