I'm confused as to how the Persuade/Intimidate/Axii conversation abilities work. From what I can gather, each levels up when used successfully, up to a maximum level of three. But just from playing through the game (and cursory internet searches), it seems like there's a lot of random chance involved in whether or not they actually succeed.

Problem is, a lot of the topics answering questions related to this either pre-date the EE release or contradict each other. For instance, the IGN guide explains the whole "random chance" mechanic, but other users say that's not the case.

Could anyone clear up how these skills work, exactly? Especially now that the game has been out for so long.

Also, is one skill used more often than the others, or are they equally spread out?

Finally, as much as I hate to muck up the game's mechanics on a first run, I'm really not a big fan of making a die roll for dialogue checks. You either have the skill or you don't - shouldn't have to see if the dice agree. Is there a mod that removes random chance being a factor, and just has the game look at your skill level?