Xenophile said:
It doesn't matter whether someone is going to save and load their game 50 times to get a success on something. That argument I find really funny. Do you really care if "joe" down the street is doing that with his game.. It's a friggin single player game. I mean if you are the idiot doing that to get one option to work that you have a 5% chance of success with, then it's your fucking time your wasting and not mine, I could give a rat's ass.
What use are those fabled "achievements" that Bethesda is putting into Fallout 3 (ones that are reflected ONLINE), if the game allows the player to breeze their way through it by just loading and saving multiple times ? It's not really cheating, either. No trainers involved. Loading and saving is a part of the game. It is what the game LETS YOU DO, BY DESIGN, therefore it is "OK". The temptation will be great to get that juicy dialogue choice when its got a borderline percentage and you're a good way through the game and you "should have it available, damn it".
Now, let's assume that Bethesda took care of the above and pregenerates all outcomes on game startup. How is that different from Fallout's skillchecks in dialogue ? Not by much.
It is somewhat more randomized and less predictable, which partially muffles the meaning of creating a distinct character at the start of the game, as the control of his fate is partially in your hands, and partially in the hands of a random number generator. That... is not a good thing.
The use of "random" only belongs to implementation of frequently used gameplay mechanics (like shooting, skills), because on average, it evens out, and adds some excitement to turn-based, not-exactly-action-packed sequences.
Random probabilities should have no place in something like dialogue. Dialogue options are not frequently reusable, each is unique. There's no fun to be added by shuffling probabilities.
What is the better design ? Instead of assigning a 70% probability to all charisma-affected dialogue choices at CHA of 7, just pre-design a specific 70% of charisma-dependent dialogue choices to be available at CHA of 7. Display the unavailable potential choices as grayed out. This allows for more customized and context-appropriate, tuned content control.
I would never implement dialogue options with probability percentage. It is a pointless design, change for the sake of change, offering no benefits other over options.