Alterego: I tried it yesterday because I've found it on the wikipedia page about life simulators. Although different, innovative and interesting, it doesn't go much in the direction I wish. But I need to play some more to be sure for it.

Crusader Kins 2: Saw some movies and found it to be very promising. Wanna check it out for sure :)

Path of Exile: Didn't have the time to really dig it. Don't know how complex is the system but in my vision, a huge extensive levelling system is not necessarily complex. But I still don't know the game and plan to give it a try soon.

Darklands: It sure looks interesting and I'll try it ASAP.

Realms of Arkania: I have it for years and still didn't play! But now I'll since I really like the description provided here.

Somebody suggested two other games via PM:

Redshirt: Looks awesome. Wish there was a demo somewhere.

Fahrenheit: Another great game which interested me.


Guys, you're being awesome! Thanks very much in advance for all your help :)

I'll put in another suggestion for Path of Exile. Aside from the already linked to skill tree the game also has a fairly robust crafting system that ties into the in-game economy (the items used for crafting are the de facto in-game currency traded between players).

Titan Quest is another aRPG with a fairly complex leveling system due to the ability to mix and match classes.

King's bounty has a somewhat interesting system within the context of a tactics game. Along those lines, HoMM5 also has a fairly complex system, although unfortunately the in-game presentation of it is rather opaque.

That sounds awful. Any way to counter that or turn it off as a setting?

That sounds great. If you hit a sweet spot to kill enemies effectively after a while it will loose its effect and you have to find somewhere else, forcing some variety.

Hmm, interesting that you liked Darklands character generator.

Well, I don't know if the game has to be a GOG game, but here are my suggestions:

1. Majesty: The Fantasy Kingdom Sim
2. MegaTraveller 2: Quest for the Ancients
3. Twilight 2000

Hi Mentao. It doesn't have to be GOG games. Thanks for the sharing :)

The most complex games I figured out are some games from Paradox Inreractive like:

Hearts of Iron Series
Europa Universalis Series
and so on.

You have to run a whole country, making policy, can lead the industry and development in many directions and make war. So winning the game is not only dependent to defeat your enemys in warfare. You can also win in making the right decisions in policy, makin alliances with other countrys and so on. The system behind these games is very complex. Every decision you make causes a reaction you may have not expected. So every further development has to be gauged well.

Vagrant Story: main levelling is done by your weapons - they adapt for the enemies they strike, while becoming weaker in other areas. And there's crafting on top of that. The character himself mostly just gains more HP and gets stronger.

Evolva: kill stuff, absorb genes, pick a mutation based on the assembled genetic material.

Final Fantasy II (real 2 not the American 2): everything improves only with use. Get beaten half to death to raise max HP. Use up all mana to get larger reserves. Dodge to dodge better. Oh, and all these thing can go down - you become dumber from using weapons.

Shin Megami Tensei 3 Nocturne: The main character gains levels as usual, but to get skills you need to level up with the appropriate demonic parasite sitting inside of you. There are more than 20 of those things in the game, each with its own unique set of skills to give you at appropriate levels. And you have only 8 skill slots. And every skill you discard is lost forever - if you want it back, you need to recruit or train a demon for your party.