Gen Con Indy, one of the city’s largest annual conventions and perhaps its most unusual, will be staying here through 2020.

Its Seattle-based parent, Gen Con LLC, announced the five-year agreement with the Indianapolis Convention & Visitors Center on Wednesday morning. Gen Con had a previous commitment to the city through 2015.

An enlarged Indiana Convention Center helped convince the organization to extend its contract. The $275 million expansion, completed in January, added 254,000 square feet of exhibit space and 63,000 square feet of meeting rooms.

“The city has committed to supporting our growth, and the people and businesses of Indianapolis have embraced our gaming culture,” Gen Con co-owner and CEO Adrian Swartout said in a prepared statement. “We are happy with this partnership.”

The four-day gaming convention, annually held in August, attracted a record 36,733 unique visitors and a total turnstile attendance of 119,707, generating an economic impact of $36 million, convention officials said. Vistors climbed by 22 percent over the previous year while game-event participation climbed 26 percent.

“Gen Con is truly a one-of-a-kind convention and we are thrilled they’ve chosen to meet in Indianapolis through the end of the decade,” ICVA President and CEO Leonard Hoops said in a written statement. “In addition to providing a tremendous economic boost to Indianapolis and central Indiana every summer, their leadership and attendees bring an energy and enthusiasm to the community.”

Visitors to Gen Con travel from as far as Germany, Great Britain and Spain. Activities span from traditional board games to exotic sci-fi contests. And it's not uncommon to see Gen Con-goers at downtown venues wearing costumes of their favorite game characters.

The convention center's expansion plans convinced Gen Con in April 2009 to sign a five-year contract keeping it in Indianapolis through 2015. But ICVA officials said in August that they hoped to keep the convention for several more years.

ICVA spokesman Chris Gahl said Gen Con is considered so important to the city's convention efforts that it was one of a dozen clients brought to Indianapolis periodically to view construction of the convention center addition.

“They were one of the many conventions we were in jeopardy of losing, because they were literally outgrowing Indianapolis,” Gahl said. “So it’s very rewarding to have them commit to Indianapolis through 2020.”

Gen Con ranks only behind the October National FFA Convention, which typically draws 55,000 visitors, as Indianapolis' second-largest convention.

The city has hosted Gen Con since 2003.