What makes a good game plot?

I was planning on publishing this here (its a bit of a rant I had on the Atari forums a while back) and since the issue came up today at Co8, here it is :-) Ted's theories on what makes a good game plot (and where ToEE let us down).

To me, a good plot is genuinely interactive. For instance, while there were all sorts of little stories in Hommlet, they mostly came down to "take object A from character B to character C, get 100Xp". They mockingly got labeled 'fed-ex quests' and very few ever felt like you were really achieving anything in the grander scheme of things in the Greyhawk world. I would call it an example of a mediocre plot (in the sense of interaction I am talking about).

Examples of bad plotting, interaction-wise, would i guess be most RTS games. StarCraft for instance had this whole convoluted plot about Alien-ripoff beasties attacking humanity (or something) but in the end, whatever the plot of each scenario, the situation was one of two things - either escape with a finite number of units, or build a base, defend it, build units and crush the enemy. The plot was irrelevant to the actual gameplay. In a game like AoE, which I enjoyed, maybe u don't mind so much, and if the final scenario is tough enough you feel some minor exultation when the closing cut-scene rolls, but as far as StarCraft went, I twice tried to play it through and both times gave up during the Protoss section - i just DIDN'T CARE. "O look, i have to build a base, defend it against a few attacks then crush the enemy...didn't I just do this five minutes ago?" I mean, u may as well be playing a random encounter / scenario as playing the campaign, there is in effect no difference.

An example of good plotting is my perennial favourite Ultima V. As you wandered around talking to people and picking up clues, you found stuff that opened up other areas of the game. Finishing a quest to find a sextant, or a grappling hook, or learning to play the harpsichord :D all had major effects on the way the game played - BUT there was very little linearity to it, you could just as easily ignore these elements and just wander round beating up monsters and raising your XP.

Did ToEE have any good plot elements? Well, one does come to mind: the gold skull. It got more powerful and useful as you went further along the quest (as you stuck gems in and such) and destroying it had a real impact on the ending of the game (never tried playing the ending without destroying the skull, don't want to!)

Anyways, thats my $0.02 on what makes a good game.