Between the various D&D groups I play in we seem to have ran or prepared to run most of the D&D campaigns released for 5e - Lost Mines, Descent into Avernus, Curse of Strahd, Tomb of Annihilation, Prince of the Apocalypse, Dragon Heist, Dungeon of the Mad Mage, Rime of the Frost Maiden, Out of the Abyss, and Saltmarsh - not to mention at least 50% of the Paizo APs for 1st Ed and most of the big 3e campaigns. Some worked, some didn't work. A few didn't get past the first few sessions - usually because I lost the drive to complete them (Princes of the Apocalypse and Rime). A few went on to be some of the most memorable campaigns I've ran in 30 years - Curse of Strahd and Tomb of Annihilation for instance.
There are a couple of things that I think I've spotted that make campaigns great or merely grate. I thought I would lay them out for a bit of discussion in turn with examples where its done well and where it falls flat. Here are my three:
- Great villains linked to a clear objectives
- Open world but within clear limits
- Meaningful NPC roleplay with clear outcomes
I don't believe its a coincidence that two of the best 5e campaigns - Curse of Strahd and Tomb of Annihilation - feature iconic villains. In both cases the players have a clear goal which involves thwarting said villains and even if the mystery of who is behind the plots is hidden at first - the goal itself is very evident and intrinsically linked to the villain. Rime of the Frost Maiden on the flip side suffers from the fact that the main villain is almost incidental to the bulk of the adventure. Auril is present causing problems, but little of what the party does attempts to correct that, and the finale location is incidental and unrelated to her. Dragon Heist has four amazing sets of villains but they barely feature in the bulk of the adventure - only appearing if the DM shoehorns them in (which works brilliantly when they do). Similarly in Descent into Avernus the lack of clear objectives that relate to Zariel mean the party are largely been led by the nose through a serious of encounters that seem to bear little relevance to the actual objectives of the villain. These villains aren't limited to the BBEG - in my current run through of Skull and Shackles the vicious first mate Mr Plugg is driving great engagement with is influential positioning. Similarly the corrupt councillor in Saltmarsh kept our party always searching for clues and a way to catch them out. Great D&D deserves great villains.
There are lots of disagreements about railroading, roads with rails, sandboxes and the like. I'm not trying to be dictatorial. Where a world is well detailed and interesting and has explorable areas you can visit in an order of your own choosing, they bring a lot of freedom and flexibility to adventures which I think many parties really thrive off. 5e is a gift for this kind of exploration and is very forgiving of wide ranging challenge ratings with many iconic creatures. It was a mistake to make the Dungeons of Undermountain sequential rather than giving the party choices about where to explore. Whereas the chance to explore the valley of Barovia bounded by its impassable mountains gives the party the feeling of being able to properly explore and discover the secrets of the lands. Barovia was packed with fascinating encounters and locations. That boundary is not optional in my opinion. The party needs to feel like they are exploring within limits - wandering amidst arbitrary locations with no fixed point is nowhere near as fun as anyone searching Avernus soon finds out. The island of Chult is bounded by the sea and you know your goal is somewhere on that island continent. Worst of all is the kind of linear encounter hopscotch found in chapter 4 of Dragon Heist or the later parts of Avernus.
Lastly (and this may be a personal preference) great encounters have great NPCs to roleplay with meaningfully. This has to be more than a five minute conversation to justify and reinforce why the PCs are killing the NPC or not. Meaningful NPC interaction involves persuasion, negotiation, trading of favours, obligations, betrayals, a bit of leverage and most importantly three dimensional NPCs have that clear goals and reasons to interact with the PCs beyond just fighting. Curse of Strahd delivers this in spades with fascinating characters to interact with - that can aid or hinder the party. Similarly in Chult a number of key NPCs can help solve the mystery of what the hell is going on.
I'm sure there are other elements that are important in making a great published campaign but I'm afraid without these three things - I'm on an uphill battle as both DM and a player. What do you think? Are these important to you, or are there other elements that matter more?