Rules designed to stop Pokemon hunters "overrunning" parks in Milwaukee County have been suspended following a legal challenge.
Milwaukee's parks appeared in Pokemon Go as Pokestops, real world locations players visit to gather in-game items.
But officials said the volume of players had "unintended consequences" and ordered games-makers to apply for permits to include parks in their apps.
The order will be suspended while the legal challenge is considered.
Several landmarks in Milwaukee's parks were included as points of interest in Pokemon Go when it launched in 2016.
But the Milwaukee County parks service said the number of players had increased littering in the park, overwhelmed toilet facilities and resulted in "trampled grass".
In January, it introduced an ordinance requiring developers of augmented reality games to obtain a permit before including the parks as points of interest in a game.
Games companies must detail how they will deal with security, waste collection and toilet provision, as part of the application process.
Critics say the requirement might stifle the development of mixed-reality games, which companies such as Apple and Microsoft are investing in.
In April, a legal challenge was brought about by games company Candy Lab.
The company does not make Pokemon Go but is developing a poker app that encourages players to visit real-world locations.
It said video games were protected by the First Amendment right to freedom of speech and claimed the park ordinance violated that right.
A preliminary injunction was granted on Thursday, so the permit requirement can no longer be enforced until the case has been heard.
Analysis by Chris Foxx, technology reporter
The case highlights how decisions made in a game studio's office can have real-world consequences hundreds of miles away.
It is no surprise that parks would like game developers to chip in for the cost of maintenance and services, if an app is encouraging large groups of people to gather there.
But since games such as Pokemon Go do not ask people to gather in the park at a given time, should they be classed as "events"?
And should game developers be held responsible for the actions of their players?
So far, the court has leaned towards "No," and has suggested parks could penalise people who trample the flower beds, or cordon them off, rather than ban games.
The next augmented reality craze is likely to be just around the corner: Apple has already released its augmented reality toolkit for game developers.
Videos showcasing impressive concepts, such as a real-world Pacman-style game, are attracting big audiences online.
These new apps could be in consumers' hands before the end of the year, so developers will be hoping a more definite ruling comes quickly.