Dungeons and Dragons

I think it's a matter of in what context the quantum ogre is used as well.

Combat is complex to balance in 5e, so encounter design takes up significant prep time. It makes sense the user a quantum ogre where the players are arbitrarily picking between rooms A and B in a dungeon. They have a fight, then the DM has time to prep a puzzle or another combat in the unused room for next week.

The poster you're replying to shows when quantum ogres are bad. World building at a basic level isn't a heavy lift, so limited prep work is wasted by fleshing out both locations. And your players won't out level a city or NPC like they will a combat. So you can always come back to that unused location later with minimal additional work.

If you’re doing good prep, you don’t need quantum enemies. You can whip up an ogre encounter on the fly instead of forcing one at a particular point.

I’d say random rolling an encounter is the opposite of choice. It’s representing the variance of the fantasy world: if there’s a 1% chance of someone traveling through a given region encountering a dragon, rolling a 100 on a d100 table emulates that.

Imagine that a DM decided to prescript combat so that every player gets down low HP before the enemy dies in the fourth round. The DM doesn’t give the enemy HP, they pretend to roll behind the screen, and they mete out damage at predetermined intervals. This happens regardless of whether:

• The rogue decides to use their inspiration after a miss to try for sneak attack
• The wizard uses Fireball for damage, tries to break concentration with Magic Missile, tried to Hold Person the enemy, or just cast Firebolt
• The Eldritch knight uses Shield to absorb a hit
• The cleric buffs and heals the party vs. focuses on damage
• The barbarian uses rage or saves it forever
• Which wild shape the druid chooses

Regardless of any of these decisions, the DM has already planned the entire thing out. Attacks hit when the DM wants them to hit, the DM makes up that the enemy is “starting to look bad” when they’re not tracking HP at all, the enemy suddenly saves against things that would be encounter-ending, etc. This is basically the quantum ogre.

Rolling in the open, letting hits hit and misses miss, suddenly makes those decisions important, because the DM can’t just lie to meet a predetermined outcome. Rollable tables are a similar sort of randomness that discourage a DM from just forcing a predetermined outcome at the player. A random generator is not even a choice at all: other than choosing when to roll it, the DM has no influence over the result.

I see the QO as a stepping stone to using random encounters, and to prepping enemy stats but not setting the encounter itself in stone.

Do you mean rolling random encounters while traveling or Rolling encounters randomly within a dungeon?

Random encounters were originally put in to add spice to long travel and make it feel like actual long time to travel and dangerous. Nowadays with modern story telling you can continue using it if you want but if you have a story base campaign they mostly just interrupt the flow.

If you want to use them for Additional XP and gold from time to time to adjust your players level gently and/or because you havent quite prepped the next area and you want to stall til next week then go nuts but see them for what they are, a purposeful time filler and making your players scared to go throught the forest.

If you mean within a dungeon then go nuts if you arent planning your dungeon fight by fight and you like the challenge of your monsters being random so your players have a more even chance, go nuts.