The Tavern

Arena is extra-dimensional branch that can appear in three forms: Arena of Mortals, Arena of Heroes, Arena of Gods.
There's only one type of Arens can appear in one game.

When the player enters a portal of the Arena he sees a large area with group of monsters. After he defeat all monsters there is a new wave. Only after defeating all the waves in the center of Arena appears lott and portal out of Arena. Each wave contains same-themed monsters (from them same branches, with the same type etc.) This is the basics. Now I'll tell more about the different types.

Arena of Mortals.
Portal can apeear in the depth of main dungeon also in Lair and in Orkish mines. 3-5 waves.
Examples of waves:
- Orks
- Animals from Lair
- Ogres
- Lowlevel demons
- Lowlevel undead
- Centaurs and satyrs

Arena of Heroes.
Portal can appear in the Derths and in the Vaults. 4-7 waves.
Examples of waves:
- Giants
- Undead
- Deep Elves
- Lair branches monsters (Swamp, Shoals, Snake pits etc.)
- Abyss monsters

Arena of Gods.
Portal can appear in Pandemonium, Hell, Realm of Zot. 5-9 waves.
Examples of waves:
- Holy creatures
- Hell monsters (from one of the Hells)
- Dragons and draconians

If this idea has a chance I can work out its details.
And sorry for the bad English. I try to speak better but it not always works.

What does this add that isn't already accomplished by timed portals and/or ziggurats?

nanozig

Variety. Early timed portals aren't have many specieses. So when you walkthrough the same sewer or occassuary for the umpteenth time that become boring. So that "nanozig"(c) can add that missing variety.

I'm a big fan of portal vaults, and particularly early portal vaults. However, I think that they should be small. As a rule of thumb, the earlier the portal, the smaller the map should be. This is for two reasons: if you die early on, it doesn't feel right to have spent thirty minutes in the special level and ten minutes in the main dungeon. Secondly, conquering a portal vault always improves the character (experience and loot), and large maps are tending towards bigger benefits. In my opinion, a number of Sewers are already too big (i.e. take too long to clear, even if the loot is alright).

This is why I am not fond of miniature ziggurats in the early dungeon. There are some ideas for early portal vaults that I'd love to try. I am somewhat working on one where you pick up an ally and then face stronger competition (no guarantees this goes anywhere, I am stuck with the lua). Another idea that should be usable is a demon pit: there are so many lowly demons (glyph 5 monsters) which amount only to chaff later on. There must be a point in the game where they are often interesting opposition.

It is impossible to make vaults that are challenging for everyone: any berserker will generally storm them (if you can come up with early Be-challenging maps that are fit for other combos, tell me), but **Be is kind of easy mode. For other, random recommended combinations, early portal vaults should not always be a win.

Well, I also have got some ideas about "more traditional" portals. Like a Limbo - that is just this "demon pit" with lowlevel demons. Or Hive - vault with ants, bees, spiders etc.
If you are interesting in, I can make topic special for them.

Feel free to do so! However, it is not very hard to just make such a portal vault. You can do it alone! (Obviously, this increases the chances to get into the game a lot.) The documentation about that is correct these days (it was wrong for a long while and who knows when it will become obsolete again? Docs are always trailing behind.)

However, if you have never made an ordinary vault (I've been out of vault reviewing for years, sorry if I missed contributions by you), you should definitely start there to get a hang of the (not so bad) syntax.

Unfortunely for now I can't make even ordinary vault. I'm trying to learn this craft but so far the results of my labors are the typical "mad skillz"
But I created a topic with some ideas of portals)