The studio behind World of Warcraft has responded to a petition asking it to run a server for the original version of the video game.

Blizzard Entertainment no longer operates servers for the original WoW so some gamers have set up their own.

The company said giving its blessing to pirate servers would damage its legal rights, but was considering adding a stripped-back realm to appease fans.

One former WoW developer called for the original game to be “preserved”.

World of Warcraft is an online multi-player game in which players explore a vast landscape, complete quests and interact with other gamers.

At its peak in 2010, World of Warcraft attracted almost 12 million subscribers, but the game today attracts about five million paying customers.

The original game from 2004 has since been updated with new instalments that some players say have materially changed the experience of the game.

Some fans have set up their own servers to play the original, “vanilla” WoW although the practice is technically illegal.

On 10 April, a popular fan server known as Nostalrius, with 150,000 active members, was closed after the threat of legal action by Blizzard Entertainment. It sparked a petition which has attracted 240,000 signatures.

“The honest answer is, failure to protect against intellectual property infringement would damage Blizzard’s rights,” Blizzard wrote in a forum post.

“There is not a clear legal path to protect Blizzard’s intellectual property and grant an operating licence to a pirate server.”

Due to the nature of intellectual property law, turning a blind eye to pirate servers would make it difficult for Blizzard to challenge other abuses of its franchise in the future.

The firm added that it could not operate its own server for the original game “without great difficulty”, but said it was considering whether opening a “pristine realm” within the latest game would appease fans.

A pristine realm would simulate some aspects of the gameplay in the original WoW within the latest edition of the game.

“In essence that would turn off all levelling acceleration including character transfers, heirloom gear, character boosts, Recruit-A-Friend bonuses…” the company wrote.

“We aren’t sure whether this version of a clean slate is something that would appeal to the community and it’s still an open topic of discussion.”

The suggestion received a mixed reaction from fans on WoW message boards.

“I would love the idea of a pristine server updated to current WoW that you could build a community around without being stuck in the old game,” said one player.

But other fans were critical: “From a personal stance, a pristine realm isn’t even what I want. Nothing in a pristine realm fixes the major issues of retail WoW for me.”

Another added: “When you actually start listing all the improvements to the game since vanilla, you see why it should stay dead… the sheer amount of people clouded by nostalgia is staggering.”

The closure of fan-run servers such as Nostalrius has highlighted the difficulty in preserving modern video games for historical record.

On Tuesday, game developer Mark Kern who worked on the original WoW, said: “WoW is an important game, it’s part of gaming history, but there’s no legal way for people to enjoy its earlier versions or see where it all came from.

“Unlike the old days, they can’t just boot up a floppy disk or slip in a CD-Rom.

“The original game is gone from the world forever and legacy servers are the only way to preserve this vital part of gaming culture.”