Not my RPG of choice, but I'm all for talking about RPGs in general.
As a GM, you're the storyteller. The other players are also storytellers, but they typically have less agency than you do when bending the rules. That depends on the type of game you're running though. Some GMs prefer running things strictly out of the box while others are cool with players suggesting narrative changes and roll with it.
My weekly Torg game is on the heroic, freeform side. I have an idea for stories, but Torg allows players to add drama with subplot cards. There might be a wandering monster, an unrealized trap, a new minion, or an unexpected hostage. Actually, I highly suggest using subplot cards in general. Torg has a very specific deck of cards for this, but you could also look up Whimsy Cards or Storypath Cards. They allow players to add some zest to a game, but the GM has to be very flexible. Maybe you intended for the group to simply invade the orc camp, but thanks to that interloper card that someone played, there's also a group of drow spies sneaking around that may abscond with a mysterious scroll if they aren't stopped.
Don't be afraid to say yes. If a player asks if there's a chandelier hanging nearby, then the player is contemplating doing something cool. Let it happen. Obviously not every suggestion is feasible, so don't be afraid to say no. The rules of improv are in play here. Embrace the "Yes and…" but also provide some outputs with "No but…" No, this tavern is too short for a chandelier, but a stick of dynamite did fall out of someone's pack and is rolling toward one of the floor lamps.
One of my pet peeves in RPGs is needless rolling. Make every die roll count. A not-so-exaggerated example is knocking down a door with no danger looming over it. The GM says to roll Strength. Nope, that 8 isn't going to do it. Roll again. Nope, not on 12 either. Keep on rolling. Oh, good, after 15 rolls, you finally beat the 19 needed to break down the door. The room is empty. Ugh, bad GM!
Instead, if the PC has the means to eventually succeed, hand-wave it if there's not a threat. There's a door, and with some great effort you break it down. Beyond is an empty room. Move on to the next action.
But dice-rolling has its place. If there is a threat on the other side, then they are aware of the PCs trying to break down the door and can prepare for the attack. Each failed roll gives them more time to prepare.
You could also use 13th Age's fail-forward mechanic. You don't roll a bunch of times. You roll once. And you succeed. But if you don't beat a certain number, that success may come at a price. You didn't beat 19 on the Strength test, so you slam into the door several times before it breaks apart but now you're facing some very prepared and buffed enemies. If you had rolled 19+ on that roll, then you kick in the door and descend upon the enemies while they're scrambling to draw their weapons.
I'm a little curious about the recently Kickstarted Over the Edge reprint. From what I read, the player rolls once to determine success or failure. It sounds like it'll be very narrative-based.
