Which version is this?

[Ningauble]

I'm not sure I know which rules to read from, my friend and I were playing our copy which is 4th edition and I kept mis-expecting things >.<

[gozik]

It is 3rd edition.
You can use this rules: https://en.doc.boardgamearena.com/Gameh ... EyJGwwJGgw

Or look for 3rd edition on BGG, but probabbly it will require to search through expansion pages.

If you need short summary, here it is.
There are some rules that differ from 4th, but they all are related only to expansions:

Echoes: Forecast is not limited in size, and playing cards from it is not mandatory. Drawing condition is different.
Cities: Endorsing price is tuck a card, not rfg
Artefacts: There are no museums achivement

The rest is the same I believe.

Also some cards have little balance changes, but you probably will not notice them unless you play competitively.

[gozik]

Also there is 4th ver in alpha now, but I know nothing about release plan.

[Ningauble]

Thanks!

[Destrucity]

Innovation Ultimate is available to play for free at Yucata.