Organizers for Gen Con, Indianapolis’ largest convention based on scale and economic impact, have sent a letter to Indiana’s governor, saying they may leave the state out of concern that a recently passed bill will allow private businesses to discriminate against LGBT audiences for religious reasons.

Update (03/26): Since this was posted, Indiana Gov. Mike Pence signed the bill, arguing its merits on religious freedom grounds. “The Constitution of the United States and the Indiana Constitution both provide strong recognition of the freedom of religion but today, many people of faith feel their religious liberty is under attack by government action,” Pence said in a press conference on Thursday.

A new “religious freedom” bill expected to be signed into law in Indiana could cost the state a big-stakes event.

The organizers of Gen Con, a for-profit annual convention focused on traditional pen-and-paper and card games, announced on Tuesday that they were considering moving the event out of Indianapolis, citing a bill passed by state lawmakers that would  allow private businesses to deny service to customers based on religious beliefs. The bill was sent to Gov. Mike Pence earlier that day.

Opponents of the bill say it would legalize discrimination against members of the LGBT community.

“Legislation that could allow for refusal of service or discrimination against our attendees will have a direct negative impact on the state’s economy and will factor into our decision-making on hosting the convention in the state of Indiana in future years,” Gen Con owner and CEO Adrian Swartout wrote in a letter to Pence [PDF]. The governor has said he plans to sign the measure.

The exit of the conference, which drew more than 56,000 people last year, would be a major loss for the city, as the event drives $50 million in spending each year. While Gen Con organizers have a contract with the city through 2020 and have no plans to cancel the contract, they say the bill could affect future plans.

(Gen Con’s call had ripple effects: Soon after the announcement, former Star Trek star George Takei, one of the most popular personalities on Facebook, encouraged his audience to boycott the state over the bill.)

Visit Indy, the city’s tourism bureau, opposes the bill. While the group hasn’t heard of other events looking to leave the state, some organizers have asked the bureau about the legislation.

“Our concern is that there could be a misperception with this bill that doesn’t paint a picture of [Indianapolis] being a warm, welcoming, hospitable place,” Visit Indy Vice President of Marketing and Communication Chris Gahl told The Indianapolis Star. “It doesn’t align with the brand that is Indianapolis, and for that matter, Indiana. Because it could impact our ability to win convention business down the road—and keep convention business—we raised our hand and said we do have a concern.”

The scene from the 2013 edition of Gen Con, which has long been based in Indianapolis. (Alize Tran/Flickr)