Hexcrawls are Megadungeons

Is this a contentious take? 

I'm not sure because frankly it seems obvious in hindsight. Hexcrawls (and pointcrawls) are essentially megadungeons, but instead of hallways we have plains and hills and forests and instead of floors we have modules and encounter sites.

I'm not actually going to argue this point, because I don't think doing so is particularly useful. Instead, I'm going to explain why thinking about hexcrawsl like this is amore useful way of thinking about things.

What Makes a Hexcrawl Good?

The ability to make meaningful and informed decisions(I stole this from Goblin Punch and I'm willing to admit that), Hexcrawls are about resource management and exploration, and both of those things require informed decisions. 

This is where most hexcrawls fail. If all you know about the adjacent hexes are their biomes, you have essentially 0 information and no way to make a choice on which one is the best one to go explore. If you go north and "oh surprise there is a river that you cannot cross!" than you feel like you've wasted your time. This makes the resource management less meaningful. It turns exploration from something you think about to something you just kinda do.

What Makes a Megadungeon Good?

Well, the ability to make meaningful and informed decisions. Megadungeons are about resource management and exploration, and both of those things require informed decisions.

Good dungeons are designed in a very certain way. They limit the players options to help them make more informed decisions. Hallways are the obvious one, you can't go from a room to any other room, but you can go from room to rooms 2 and 3. Doors and gates and keys are another way, be they literal doors or gates, flooded passageways, an enemy too difficult to fight head on, or anything else.

Restrictions give us the information to make more informed decisions.

Restrict Your Hexcrawls.

Not, restrict as in size (though you should do that too), or restrict as in reducing the number of monsters you use.

No, restrict your player's ability to go form hex to hex. Use doors and gates to help focus direction. Remember, if you have infinite equal options, then you have no options because you're essentially choosing at random. Limiting options is not limiting creativity

Megadungeon Hexcrawl Design

In my opinion, there are two options for hexcrawl design:

1) Site as dungeon level

2) Region as dungeon level

This is a choice of how grand your scale is. If your sites are dungeon levels, then your goal is to design a hexcrawl where each adventure site is approximately one levels worth of contentt, and if you choose region as dungeon level you'll have one levels worth of content spread out over multiple sites and open areas.

Figure out which you want, then seperate different sites or regions with doors and gates,

In order to go from the snake temple to the crystal caves, you have to find a way through the spooky forest full of spiders! How do you deal with the spiders? I don't know, but you're going to need gold and the best way to get gold is up in the snake temple.

Obviously, this doesn't mean "turn your hexcrawl into a glorified line. It's still a hexcrawl, encourage exploration. Even if sites are a dungeon level, introducing smaller places to explore or interesting places to find make the map feel more alive! And you can always have multiple options. The crystal caves might be level 2 of our "megadungeon", but the spider tree is level 2a, and both are equally valid to explore, and the spider climb boots in the caves could be used to skip up to level 4 of our "megadungeon" up in the mountains.

Basically: think about how you would connect your hexcrawl as if it were a megadungeon, and then shape things around that.

Note: My examples here are all talking about site as dungeon level design, because I think it's easier and more obvious. Region as dungeon level is simply, in my opinion, harder to design because there's just more content. If the spooky spider forest is meant to be enough content to level up, you'll likely need several smaller dungeons, a number of non-dungeon adventure sites, and all that.

Second Note: Do all the other things you'd do in a megadungeon too. These dungeons can(and should!) have factions! There is no reason to think the spiders don't have their own goals and won't interact with the world seperate to the party. The party might ignore the spider tree, but it's hard to ignore the spiders when they're invading level 3, the orc castle.