Personally – I will risk a thesis that story HAS TO be simple in cRPG to make a good cRPG.
Good story is, most of times, a complicated story. A complicated story – with many dependences, specific characters, sub-plots and cause&effect relationships – is hard to interact. The story should be so simple that any type of character could fit into it: from dwarf barbarian with 0 int. to female elfish bard with 999 charisma and no fighting skills. In p&p RPG it looks in a different way – because GM could shape the story and match it to his specific group (at least a good GM – not those guys who write the adventure without knowledge about their players characters or use the official modules).
In the story-heavy cRPGs I usually feel that my character do not fit to the plot. Take PoE. I’m dwarf barbarian from Living Lands. I have come to Deerwood in searching for fame and fortune. I’m simple mercenary who hates magic, souls, mysticism and all that jazz. So what is the point of following the story of the game? There are many games like this. To handle this problem the player usually receives some secondary identity: “the Chosen One”, “the Bhaal Spawn”, “the Dragonborne” etc. And, finally, you do not play the game as a dwarf barbarian but as a “Chosen One”, “Dragonborne” etc. I do not like this approach.
So – the best story, for me, is a frame story, with very simple plots. Compare two quests from two games: the “bridge quest” in the first town of Arcanum and the “conspiratorial” quest in Marharth of Skyrim.
· Arcanum. So roughly simple. You have a bridge to cross. The bridge is occupied by bandits. End of the story. But so many opportunities. The player can ally with the local officials or with the bandit leader. If allied with sheriff – we can kill bandits or persuade them. Or we can ignore whole this conflict, just steal the key, sneak through the bridge and say “goodbye” to everyone. All approaches has some minor dialogue variants (“I will make it for money” or “I will make it for an idea”) and some minor future consequences. It is a good cRPG.
· And in Marharth? We have a quite complicated political-criminal plot (let me be generous for Skyrim…). And what we can do with it? Nothing. We are just running from one quest marker to the other and watching the brilliant story. It is not a good cRPG. All Withers 3 quests are exactly the same thing – dialogues are better but gameplay is also week.
So the best thing you can do as a cRPG designer is, in my opinion, to write a simple plot like: “Armies of DARKNESS are approaching the FREE LAND of NEVERLAND – oh mighty PLAYER – do what you want with it”. Join the DARK LORD or the GOOD KING (or ignore everyone and watch the world burn), use any of your skills, recruit companions you like etc.
The good example of this approach is the first half of Gothic 1 and 2. What is the story, what is your goal? Very simple – you have to become someone IMPORTANT, that’s it. The rest depends on you: join the militia or rebels, study magic or art of war, make friends and foes all around the island. And it works.