These have been a rough few days for Skyrim modder James Ives. "I've received countless death threats, attacks and hateful comments," he tells Polygon. "Just about everything you can think of."

Note: Subsequent to this story being posted, Valve announced that it would be ending paid mods for Skyrim.

Ives, aka Jimo, is one of the handful of developers and artists included in a new Steam initiative that allows modders to charge for their work.

The notion of an open market for paid mods has been deeply controversial. A Change.org petition has thus far attracted more than 130,000 supporters, who are keen to keep mods free.

Valve managing director Gabe Newell took to Reddit over the weekend to answer questions about the changes. He said that charging for mods increases quality and value, and helps creators sustain their work.

"Our goal is to make modding better for the authors and gamers," he said. "If something doesn't help with that, it will get dumped. Right now I'm more optimistic that this will be a win for authors and gamers."

It's fair for someone to be compensated for their work and time.

Mods are modifications to existing games that allow new ways to experience the game. They range from simple items like goofy weapons, to entire mini-campaigns. Revenues from mods within the new plan are split between Valve, the game's publisher and the modder, who receives a 25 percent cut.

Polygon spoke to two of modders involved in the program — Ives and Thiago Vidotto — to ask their views on paid mods and on the hostile reaction to the changes.

Vidotto is a character artist and animator who created weapons based on DOTA swords for inclusion in Skyrim. He began modding on games like Quake in the 1990s and now makes his living from his work.

"I think it's fair for someone to be compensated for their work and time invested on something. No matter what kind of job," he said.

He added that he always expected some kind of debate because "every big change causes some controversy: People are used to free mods. Introducing the option for people to charge for their work affects usual behaviors."

Vidotto said he has received unpleasant messages accusing him of "destroying the gaming world," but he added that he can understand the point of view of those who value free mods.

"Some people mod a game because they like it and want to put their personality into it," he said. "Most of them are doing this as a hobby. They may not feel comfortable charging for something they enjoy doing.

"But some modders are really good at what they do. They create a whole new experience for a lot of gamers. Their work demands a lot of time and effort to produce. I believe it is fair for them to be compensated for their work.

"Modders should be free to decide how their work is distributed, and not forced to keep working for free."

Ives created a short quest based on Half-Life, which he sells for $0.49.

"I think anything that compensates content creators for their work is a good thing," he said. "Content creators on platforms such as YouTube and Twitch are able to make a living doing what they love. I think it would be great if that could be extended to modders."

In his Reddit AMA, Newell said that the paid mods have raised about $10,000 since they were introduced late last week. Revenues are likely to increase as more games and publishers join the scheme.

Earlier this year, Valve announced it had paid out more than $57 million to Steam content creators. The company's own games, including Team Fortress 2, Dota 2 and Counter-Strike: Global Offensive, let players purchase community-made items through their respective game stores. Many third-party games also support Steam Workshop.

The new program allows modders to set their own prices in a market uncurated by the publisher or the retailer. There are refund protections in place. Valve has also announced a plan for modders to let consumers set their own price through pay-what-you-want and donations.

"It was essential to us that our fans decide what they want to create, what they want to download, and what they want to charge," stated Bethesda, when the plan was announced. "Many of our fans have been modding our games since Morrowind, for over 10 years. They now have the opportunity to earn money doing what they love."

The Change.org petition disagrees. "Mods should be a free creation," it states. "Creations made by people who wish to add to the game so others can also enjoy said creation with the game."

In an open letter to Valve and to Bethesda's parent company ZeniMax, the petitions adds: "This development can create a huge hole in the PC gaming community. It will also flood the Workshop with thousands more 'mods' that will literally do nothing productive to the game. This will also hurt your companies reputation."

Ives said that he always expected a negative reaction, but that many who argue that free mods will disappear are not correct. "There will always be free mods, that's not going to change," he said.

In a blog post, Bethesda also backed the notion that most mods would remain free. "But we also believe our community wants to reward the very best creators, and that they deserve to be rewarded. We believe the best should be paid for their work and treated like the game developers they are. But again, we don't think it's right for us to decide who those creators are or what they create."

In the meantime, some modders are angry about the 25 percent cut being offered for content. "I am a little offended that Bethesda believes they and Valve deserve 75 percent of the credit for my work," wrote Taleden, maker of the Trade Routes mod, in a Reddit post.

Others see problems distributing income among teams. "It does make me wonder how well Bethesda and Valve thought this through," wrote Arkaash from Archon Entertainment, best known for its Heimfeigr dungeon exploration mod. "Many of these mods are created by teams, and assuming more than a couple of people contribute, there is no way the money from sales could be distributed between members in a fair way that everyone is satisfied."

But among modders and developers who have come through commercial systems, the principle of paid work seems to be welcomed.

"I earn a good living making maps for Counter-Strike," said onefmp, in a Reddit post spotted by Rock Paper Shotgun. "By sending the signal that you hate when modders and mappers charge money for their stuff, you're saying I should go work for generic AAA game developer, and that kinda sucks. Because the freedom I have thanks to Valve and the Steam workshop means a great deal to me."

Garry Newman, maker of Garry's Mod and Rust, posted a blog update stating that free mods would always continue and that "opportunity is never a bad thing to give people." But he also called for a greater revenue cut for modders, saying that "it feels like someone is being a greedy asshole. This is something that will get better with time."

Bethesda's blog post sought to defend the revenue share. "The 25 percent cut has been operating on Steam successfully for years, and it's currently our best data point. More games are coming to Paid Mods on Steam soon, and many will be at 25 percent, and many won't. We'll figure out over time what feels right for us and our community. If it needs to change, we'll change it."

"This new system gives modders support for their work. They will be able to spend more time resulting in better content to the community," said Vidotto. "It is a win for both sides."

"With the introduction of paid content it can potentially attract modders who may have otherwise not created content," said Ives. "That increases choice and the overall experience for the user."

He added that differences of opinion are something that can be worked out. "The community needs to have a proper discussion about it. Given time I hope people will be more open to the idea as there are a lot of positive things that can come of this."

Polygon requested a statement on reactions to the paid mods initiative from both Valve and Bethesda, but received no reply.