WotC's D&D adventures consistently demonstrate a failure to imagine how their designs will actually play if they're run according to how they're written. There's a vivid example of this in Tomb of Annihilation. (1/x) https://twitter.com/hexcrawl/status/1307080174169718784

Outside the Tomb of the Nine Gods (the big dungeon at the end of the adventure), we find Area 3, the False Entrance encounter. (2/x)

It's a trap. Once triggered, a stone block slowly begins to lower where you see the dotted line on the map. To slide under the block, Indy-style, you need to succeed on a DC(10) Athletics check. (3/x)

Any character who fails the check is trapped. Caustic, poisonous gas fills the now-sealed area. Trapped characters must succeed at a DC 15 (!) Constitution save to avoid 2d10 damage. Trapped characters must make this save for TEN ROUNDS. (4/x)

Can the characters escape the area before the ten rounds are up? They cannot. Can they stop the gas from filling the room? Yes, by making SIX DC 10 Dexterity checks to plug the holes through which the gas is spraying. Each Dexterity check counts as an action. (5/x)

It's fair to assume that when the trap's triggered, everyone at risk will try to dive past the lowering stone block. What if one character fails the DC 10 Athletics check? Any experienced D&D player knows there's a good chance of that. (6/x)

For example, no one would blink if a wizard or warlock failed that Athletics check. Their odds weren't good! Let's assume that one character gets stuck. What do the next few minutes at the table look like? (7/x)

For TEN ROUNDS, the trapped character's making a DC 15 Constitution save. As written, there's no way to escape this trap. What's the DM supposed to do? Entertain a few rounds of futile action before saying, "Look, there's no way to escape according to the rules." (8/x)

Then what? "You've got six rounds left, so just make six saving throws and let's see how much extra damage you take." Can you imagine this happening at your D&D table? It would destroy the mood and just plain suck. (9/x)

What if the character(s) try to plug the holes issuing the gas? Here's what the text says: (10/x)

Let's imagine this sequence if it was run as written.

The character tries a Perception check. If they FAIL, then they're just screwed for the rest of the time unless the DM mercifully lets them keep repeating the failed Perception check. (11/x)

Once they succeed on the Perception check, they need to start making Dexterity checks. Even if they're DC 10, there's still a chance that one or two will fail. That's potentially 7-8 rounds of gas exposure. Remember, each Dexterity check is an action! (12/x)

Maybe two characters are trapped and they plug all the holes in 4-5 rounds. They're safe now, right, and they just need to wait a few more rounds for the trap to reset? Read more carefully. (13/x)

This is from the preceding paragraph: (14/x)

Once the tunnel seals, gas begins to billow into the area and the TEN ROUNDS of Constitution saving throws are underway. If my hypercompetent players can seal the gas holes in just 4 rounds, the space is still presumably filled with gas, right? (15/x)

So what does plugging the gas holes accomplish? It doesn't turn on a fan that evacuates all of the prior rounds' gas. It just prevents MORE gas from being released. But there's still enough gas to cause harm, because we've been making Con saves this whole time. (16/x)

As written, this encounter imagines a terrible experience at the table. A competent DM would quickly step in to fix this terrible design. But that's the problem. (17/x)

How does terrible design like this (and the plesiosaur encounter in Alexander's thread) get through WotC's design process? I suspect it's because WotC's designers are themselves highly-improvisational DMs. (18/x)

An improvisational DM doesn't care too much about what the adventure says because they'll change it on the fly. The encounters are suggestions. Published adventures shouldn't be written with improvisational DMs in mind. (19/x)

It makes you wonder whether WotC's designers even play D&D at all. If they do, aren't they playtesting their own adventures? (20/x)

Are WotC's designers even playing with the rules they write and publish? If they played by their own rules, they would have spotted this absurd trap design, this fun-destroying grind. How can we trust the rules when the game's own designers don't seem to use them? (21/21)

I've played D&D for 35+ years. I understand the house-rule, make-it-your-own culture surrounding it. WotC's designers don't have the luxury of relying on that tradition. They write the rules. If they don't show confidence in the rules they write, that's a red flag. (22/21)