Imaculata
Hero
I think I fall somewhere squarely in the middle of this discussion. I think a certain amount of shifting things around is fine. I have picked up a good plot point or two from the players on rare occasions, just because what they came up with was something that fit the narrative well, and didn't contradict anything that had been established. Most of the time though, I'm way ahead of them and every twist is carefully set up.
I have also on occasion waved away that last hitpoint of a monster, in the interest of coolness and speeding up a battle that was outstaying its welcome. I have also had enemies flee, most of the time because it was in their nature, but also to shorten a battle (rarely to make it easy on the players).
On rare occasions I have moved a clue or important item so that the players would find it. This can be a minor correction when I feel I haven't properly foreshadowed something. Most of the time though, items remain where I placed them when designing a dungeon.
During battles, I'll sometimes have reinforcements show up to make a battle harder, or drop a planned wave of enemies to make it easier. But whatever is on the battlefield, I play to its max efficiency.
However, when the pc's are on the ropes and about to die, as long as they are not low level (1-3), I do not spare them. My monsters will attempt to kill them and prevent them from dragging away their wounded to safety, that is as long as the monsters aren't in a similar situation. My monsters have goals too. One of those goals is to kill the pc's, the other might be their own survival. I don't pull my punches as a DM.
I have also on occasion waved away that last hitpoint of a monster, in the interest of coolness and speeding up a battle that was outstaying its welcome. I have also had enemies flee, most of the time because it was in their nature, but also to shorten a battle (rarely to make it easy on the players).
On rare occasions I have moved a clue or important item so that the players would find it. This can be a minor correction when I feel I haven't properly foreshadowed something. Most of the time though, items remain where I placed them when designing a dungeon.
During battles, I'll sometimes have reinforcements show up to make a battle harder, or drop a planned wave of enemies to make it easier. But whatever is on the battlefield, I play to its max efficiency.
However, when the pc's are on the ropes and about to die, as long as they are not low level (1-3), I do not spare them. My monsters will attempt to kill them and prevent them from dragging away their wounded to safety, that is as long as the monsters aren't in a similar situation. My monsters have goals too. One of those goals is to kill the pc's, the other might be their own survival. I don't pull my punches as a DM.