Hussar
Legend
But that would be a huge change for the game- making magic unreliable. Mord's Mansion is 100% effective for what it does. There are no "random encounters" when you use it. Same as most of the magic in 5e D&D. Yes, we can keep trying to add "challenges" when the party uses Leomund's Hut or Goodberries or this or that or whatever. There are two problems with that though.Maybe it isn't impossible and there are things that live between dimensions that can sometimes get into a pocket dimension. Maybe the big spells have dangers and opportunities built in, that tie in with the general rules for exploration, laid out in the chapter on exploration in the PHB. Tasha’s also has expanded supernatureal terrain, and Bigby’s has places made to challenge higher level parties.
1. The casters are now driving the challenges of the game. We're not adding in random encounters that make sense for the adventure, we're adding in random encounters or events to counter using these spells. The only reason that these events are occuring is in response to the players using these spells. Which, at the end of the day, runs counter to why we use these spells in the first place. The whole point of using these spells was to avoid encounters and make resting safe.
2. And, I'm not sure getting into some sorts of magical arms race with the players is healthy. Well, the players now have resource X, Y and Z, so, we must up the challenges for exploration to match. It's essentially just a treadmill. Get stronger, face stronger opposition, get stronger... Again, the reason we're doing this is in response to the casters.
It's an arms race that I'm not interested in because it also has the knock on effect of making players realize that if they want to engage in the game, they have to play casters. Your fighter isn't going to be of much use traversing the Elemental Plane of Water, where you need things like Water Breathing, some sort of magic that gives you a swim speed and so on. All of that comes from the casters.
The tension between the magic system and exploration is very difficult to resolve.