e926 is sfw in the sense that it has all the art from e621 that doesn't have visible bits or gore. Expect a lot of extremely suggestive or outright fetishy stuff though.
The dice determine success or failure, but your strategy can have different outcomes. If you're offering a bribe to the guard the DM has to figure out how much it costs you, wheras if you're telling him a dragon is attacking the south gate, he might be pretty pissed when he comes back.
And if you don't have "charisma" irl and have no idea either of the above are options...think about charismatic characters in books, movies, tv. What tactics did they use that you can crib?
Of course, if you know you have a seer in your party, you can plan ahead and come up with some prepared scenes. They don't neccesarily have to be predicated on what's going on near the players either; they could, for example, foresee the bbeg tormenting his captives - get some flavor about how evil he is, maybe some plot-relevant information to use later, but it doesn't actually depend on which level of the dungeon they're on or whatever. Obviously, this depends on the details of exactly what spells they're using and in what system.
But also, wouldn't you like to buy some of our paid mods?