Unstable Portal

Unstable Portal is a rare mage spell card, from the Goblins vs Gnomes set.

Lore

Portals are a line of useful Mage utility spells that allow the caster to transport themselves and their party members to one of several fixed locations (including all friendly capital cities).

The art for Unstable Portal depicts a portal to Ironforge. This card shows the city's snowy exterior, while Ironforge Portal shows its molten heart.

Trivia

• The artwork for this card comes from the World of Warcraft Trading Card Game "March of the Legion" series, for the card Portal.
• This card was hinted at by the first Innkeeper's Journal blog, Patron Dispenser, which revolved around mage portals bringing customers to the inn. It also featured the card art later revealed to be used in the Unstable Portal card.
• Curse of Naxxramas' Webspinner served to "set the stage" for the later introduction of Unstable Portal and the various piloted shredder minions in Goblins vs Gnomes, employing a similar design but with a far greater degree of RNG. Ben Brode states that players responded "very well" to Webspinner's random generate ability, and as a result the designers "doubled-down" the mechanic for Goblins vs Gnomes. The spell appears to have also inspired the five Portal spells added with One Night in Karazhan.
• The location seen through the portal is the dwarven city of Ironforge, making this a literal Ironforge Portal, although that card was not added until nearly 2 years later.
• When Medivh is the mage player's hero, a voiceline will play, saying "And from the portal comes...!" presumably from a younger Medivh.