Riot Fest 2012 is going to be a major bash. Organizers have just announced a slew of new additions to the bill, which will make the inaugural try of hosting an outdoor event one for the ages.

The latest additions include Andrew W.K., Dead Sara, Hot Water Music, Imagine Dragons, Neon Trees, the Adicts, Minus the Bear, Pegboy and more. They join a bill that already featured headliners the Offspring, Rise Against and Iggy and the Stooges, plus Gaslight Anthem, A Day to Remember, Elvis Costello, Dropkick Murphys, Coheed and Cambria, the Descendents, and more.

Single day tickets are currently on sale here, with only a few 2-day and 3-day passes remaining. VIP passes are also available at the Riot Fest Chicago website.

The music weekend runs Sept. 14-16 and will take place at both the Congress Theater on opening day and later at the Humboldt Park grounds in Chicago. The full daily rundown can be seen below.

There are also Riot Fest events being staged in Philadelphia (June 19, Festival Pier at Penn’s Landing), Brooklyn (Sept. 8, Williamsburg Park), Toronto (Sept. 9, Fort York: Garrison Commons), and Dallas (Sept. 22, Gexa Energy Pavilion).

Friday, Sept. 14 (Congress Theater)

The Offspring

Neon Trees

Pegboy

Dead Sara

Saturday, Sept. 15 (Humboldt Park)

Rise Against

Descendents

Coheed and Cambria

Dropkick Murphys

Gaslight Anthem

Slapstick

Hot Water Music

Andrew W.K.

Minus the Bear

Less Than Jake

GWAR

August Burns Red

Frank Turner

The Adicts

Nobunny

A Wilhelm Scream

Teenage Bottlerocket

Screaming Females

Off With Their Heads

Deals Gone Bad

Larry and His Flask

The Story So Far

Environmental Encroachment

Fireworks

Sunday, Sept. 16 (Humboldt Park)

Iggy and the Stooges

Elvis Costello

A Day to Remember

Gogol Bordello

NOFX

Alkaline Trio

Jesus and Mary Chain

AWOLNATION

The Promise Ring

Chiodos

Built to Spill

Imagine Dragons

Reverend Horton Heat

Fishbone

Screaming Females

White Mystery

The Henry Clay People

Sister Crayon

Japanther

The Infected

Environmental Encroachment