Is there a flow chart or YouTube video that details what games you need to play in what order for newbies of the series like me? I started playing Cold Steel I on the PS Vita last week, and I really liked it. I already purchased Cold Steel II, and will eventually buy Cold SteeI III on the PS4. Now I'm hearing there's a whole bunch of other older games in the series that takes place in the same universe I didn't know about.
Easy:
-Trails in the Sky First Chapter, Second Chapter and The Third are the original trilogy, if you already started Cold Steel I, you can finish it and then play the original trilogy. Cold Steel I is a good introduction to the saga, but the original 3 games are the first story in the kiseki universe, and present lots of characters and plot lines that will be important later. Best way to play them is the Steam version (or other PC versions), as the translation was improved and lots of QoL changes were introduced compared to the PSP version. Also the Third is only on PC.
-Trails from Zero, Trails to Azure are the two games of the Crossbell Duology, and should be played after the Sky Trilogy. The events in the game happen at the same time as the events in the Cold Steel I and II games, so in a way playing first Cold Steel will spoil some things, but it's fine. There are no official english releases, a fan edit project is currently ongoing for Zero and Azure has a fan translation that is not that bad from what I've heard.
-Cold Steel III and IV are both a follow up to Cold Steel II and Azure, and having played all the previous 7 games is the optimal way to play them, as they continue plot lines from all the games.
Best ways to play the games (taking into account the already released games):
-Sky Trilogy - Cold Steel I and II - Crossbell duology - Cold Steel III and IV
Falcom seems to be interested in bringing the Crossbell games to modern platforms, so maybe this means that in a near future (5 years or so) we will see them translated officialy, but at this moment only Cold Steel III is confirmed from the 4 "unlocalized" games.