Portal

This page is about the dungeon feature. For the card, see Portal card. For the (obsolete) spell, see Portal (spell).

A portal is a (generally) temporary gateway to a special level. Each such level has multiple possibilities for its exact layout and inhabitants, but always follows a specific theme. You will almost certainly encounter some of these in every game, but it is extremely rare to ever find all of them in a single run-through. In the console version of Crawl, portals are represented by the ∩ glyph.

Portals can be silent or announced. Bazaars and Labyrinths always announce their presence when you first enter the level, and periodically sound out afterwards, giving you a hint as to their distance and how long they will remain open. Silent portals will not generate any messages when entering the level or exploring, but you can still get an idea of the remaining time once they are in sight by examining the entrance. Volcanoes, Ossuaries, Sewers, and Ice Caves are all silent unless in your direct line of sight, despite being timed.

When a portal times out somewhere out of sight, you may get a message such as: "The floor vibrates strangely!" Treasure Troves and Ziggurats won't ever time out; of course, after they are used once, they may not be entered again.

The following comprises all known portal levels, with their in-game description and a brief explanation:

Bailey: A flagged portal; Ranged weapons and/or a slugfest with orcs, gnolls, and goblins.
Ice Cave: A frozen archway; Assorted frigid monsters and ice statues abound. Bring cold resistance and watch your potions.
Labyrinth: A labyrinth entrance; Find the exit, beat the minotaur guarding it. Bring extra food.
Volcano: A dark tunnel; Everything is on fire. Including you and your scrolls, if you forget your fire resistance.

Late Game

Wizard Laboratory: A magic portal; The private laboratories of any one of several strange characters.

Anywhere

Bazaar: A gateway to a bazaar; Shopping trip!
Malign Gateway: A portal to somewhere; Not a true portal, but the short-lived result of a spell: eldritch tentacle imminent. Walk into it to blink, if you really want to.