I am preparing Princes of the Apocalypse as the very first 5th edition Dungeons & Dragons campaign for a group of players experienced in previous editions (mostly 4E for the last years). PotA is designed as a sandbox campaign, players are allowed to go anywhere they want. But the dungeons have a specific level order, which isn't shown to the players. So level 3 players could decide to go the level 3 dungeon first, or they could go to the level 6 dungeon first, and from there directly descend into the level 9 dungeon. Even with the bounded accuracy of 5E that isn't likely to go well. I've read some advice to just transform the adventure into a linear one, but that appears somewhat heavy-handed.
So I was wondering how the DMs who ran PotA as a sandbox managed to let their players know if they had for some reason gone into a not level-appropriate region without just killing them all. I'm all for players making choices, but they have to be meaningful choices, and if the players simply get no clues at all as to the "supposed" order of the dungeons they can't make a meaningful choice to tackle a harder dungeon. Any choice they would make would just be random chance.
So I was wondering how the DMs who ran PotA as a sandbox managed to let their players know if they had for some reason gone into a not level-appropriate region without just killing them all. I'm all for players making choices, but they have to be meaningful choices, and if the players simply get no clues at all as to the "supposed" order of the dungeons they can't make a meaningful choice to tackle a harder dungeon. Any choice they would make would just be random chance.