Single huge level Vs using a hub system

Like if somebody just made like a massive ultra complex level that lasted for 10 hours and had tens of thousands of tags and linedefs specials and vast amounts of enemies would there not be any bugs or some other unexpected errors?

The reason I ask is that I am planning my own SP adventure and am considering to use hubs, but first I want to know if there is actually any advantage over using hubs Vs just making one single ultra massive level. What are the perks and cons of a single large level vs hubs?

Smaller, bite-sized chunks of anything are usually more digestible than giant single blocks. People like natural breaks: it's why books have chapters, why albums are broken into individual songs, and why even classic symphonies have individual movements.

Doom maps are no different, especially if there are natural breaks in the experience. There's no real upside to squeezing everything into a single map over using a hub and different levels, especially given (presuming you're targeting GZDoom) it supports holding a map in memory so it doesn't reset if you leave it and come back later.

4 hours ago, hardcore_gamer said:

Like if somebody just made like a massive ultra complex level that lasted for 10 hours and had tens of thousands of tags and linedefs specials and vast amounts of enemies would there not be any bugs or some other unexpected errors?

You will end up with performance problems faster than people will have a chance to complain about the length, let alone trying to actually work with and maintain a map that large.

A single huge level is more "immersive" in a way, as you can more easily have things like monsters chasing you seamlessly across the map. With hubs, you'll create noticeable transition points, even if you try to make them look seamless, an observant player can tell. For example perhaps they killed an imp in the corridor that transitions between two parts of the level, so when they're on map A they see the imp corpse, and when they're on map B and look back they don't see the imp corpse.

With ports that (optionally) show you level statistics during the game, there is another noticeable gameplay effect in that you get to know how many monsters, secrets, and items are in a section of the map when it's split into parts of a hub; whereas with a single giant maps all sections are merged together in the tally. So if you have a map made of areas A, B, and C with 10 secrets in A, 5 in B, and 0 in C; the giant map will show 15 secrets for ABC while the hub will let the player know there's a lot to find in A but there's no need to bother searching for secrets in C. Same for items and monsters.

The giant map also makes it easier to have things happening across the entire map at once. For example if you have a switch in area A that opens a door in area B, then you can show that by having a camera texture displayed on a nearby monitor showing the door opening and the player won't be too confused. (Might be annoyed by the backtracking, but that's another topic.) With a hub, you can't do that. You can simulate it by recreating a copy of the door room of area B in area A for the camera texture to work, but don't forget that you need to run a script on area B to actually open the actual door too. It's kind of less convenient.

With a giant map, things keep happening everywhere. If a player leaves area A to go to area B and left an archvile behind, that archvile will be able to go around resurrecting monsters left and right, so that when the player goes back to area A, there'll be monsters waiting. With a hub, once the player leaves area A, time is suspended in it and nothing happens. The archvile won't be resurrecting anything while the player is away.

On the other hand, hub maps are definitely much better for performances. The transition points are also good places for a player to save and quit so they can do something else than playing for a while, which is not a bad thing to have on a very long map that people may not want to complete in just one sitting.

Both Bauul and Gez make good opposing points.  But I'd throw in...make whatever you feel more comfortable doing.  I've personally been wanting to make a large adventure map in the vein of the individual Counterattack levels, but hub connected worlds are also very interesting to me.

I will say if you make a large map...you probably don't want it to take 10 hours to beat...just saying.

Personally I am font of large maps, which afford ample opportunity to explore the lay of the land.

But,

a large map with lots of stuff going on reduces the experience to a slow moving slideshow.

I literally had to cut my map into half to get a half ways decent fps of 35.

I also make and like big maps, but using hubs is much better. Not only they let the experience flow better through the player, also they make the game more interesting. Especially with every next level rising up in difficulty. Or at least until some point. 

I think you should definitely make a giant ass map. But only if you are a very creative and disciplined person and can pull it off: making a giant map is exciting, because it's an ambitious undertaking, and it can fail terribly, or succeed amazingly. It's easier for such a map to fail terribly because no one will want to push through a mediocre map that they know is going to take ten hours. And to think you spent 4,000 hours building this opus of grandeur for it to play like crap and look like crap; what a very sad thing that would be! 

So if your idea of making a map fun to play is putting in a bunch of monster teleports like every other shitty ass mapper on here, then please save yourself the colossal waste of time your map will be and instead go outside into a raging snowstorm and play handball. -- Sorry... I've let myself get carried away again. The compulsion to stress the heinousness of monster teleport abuse is very strong in me. The overuse of monster teleports is basically as bad as cut scenes in the middle of a high speed race in Need For Speed Hot Pursuit. A ten hour map should have maybe three separate instances of monsters teleporting in. It needs to be rare enough to create a surprise. Spamming this once wonderful mechanic has become a cheap and sad affront to Doom. 

Making a massive adventure map is a great challenge for the author to create a sense of progression from one area of the map to another. It is a great opportunity to weave together seamlessly one theme into another. Maybe the map starts out with a Doom 1 style military base, then segways via a not-very-big maze to an outdoor/rocky area, that is also not too big, which then leads to the mines, which can be absolutely, mindblowingly HUGE (and think, very deep, like Moria) but with easy navigation from one entrance of the mine to a nearby exit to the next themed area, for those who don't like spending hours lost in a dark, labyrinthine hell.  But of course, for those who do like to get utterly lost and terrified in a labyrinthine hell--who are most certainly in search of adventure and peril--great terrors and great rewards would greet such a rare and bold adventurer. He would do battle with great fire demons in giant, underground halls, and he would sneak down tight, winding corridors and through murky pools and find secret keys and strange, powerful weapons and be chased up steep, winding stairs by terrible screeching ghosts. Hidden levers would reveal mysterious, secret passageways that would hold a great secret of the Earth that only you, the author would know, but which you could deftly hide deep within the mines of your giant ass map. 

And because your map would be a map of great mystery, whenever the adventurer would find himself returned to a place he had been to before, something would be different there: a wall would have risen out of nowhere, while another would have come down, unleashing a horde of specters or a rabble of lost souls. Or one half of the floor of a room would have lowered revealing a hidden passageway, down which your adventurer would boldly go to discover new regions of your map that he had hitherto been unable to access, but which would eventually lead to the farthest, and strangest, reaches of your map. 

Oh yes, a colossal map could be the greatest achievement in all of Doomdom. One which would be heaped upon with every praise and cacoward known to demonkind. It could be the glory and rebirth of Doom, ushering in a new age of Doom greatness, hearkening a new generation of doomers and mappers ahem, designers alike, bringing to a close one Age, tired with mimicry, and old with the tireless repeating of rehashed ideas and precepts, and signaling the start of another, greater one, with truly great architecture, atmosphere, transitions, pacing and gameplay. All because of one, singular, magnificent, mind-blowing map that you boldly, fiercely, and fearlessly set out to make, dashing aside caution and words to the wise. You, the hardcore gamer, more hardcore than all the rest.

Are you really up to the task?

I prefer big maps over hubs, but check out the wad junko, a old wad, but that really impressive for what it is

Despite the size of the grid in the editor, your map must fit within +/- 16K in both X and Y, or you risk bizarre bugs popping up. I have experienced such bugs myself, forcing me to shrink my map. In my case, I was taking melee damage from a monster in another part of the map.