Multiplayer in the Uncharted franchise has been a contentious affair. Some players love the addition; others feel it can be an unnecessary distraction from the game's chief appeal, its rich, character-driven campaign.

While the developers at Naughty Dog are still committed to providing multiplayer for their games, they're starting to experiment with different ways to deliver that experience.

Today, Sony Computer Entertainment America and developer Naughty Dog launched a free-to-play version of Uncharted 3's multiplayer. Players can sample the competitive elements of the shooter's gameplay without spending a penny. But once they want to level up their character past a certain point, or play the cooperative modes, they'll have to start paying cash, ranging from $5 to $20 to buy level cap increases and co-op modes.

The game is free up to level 15. If you want to continue leveling after that you have to pay about $5 up to level 25, or about $20 if you want the cap removed altogether. Fortunately, even when you're capped out, the game will track your experience, in case you change your mind and decide to unlock the cap down the line.

This a la carte approach to gaming hits the same day that the publisher is releasing a downloadable version of the Game of the Year edition of Uncharted 3 for about $40. It's also a way for developer Naughty Dog to start figuring out how it wants to approach multiplayer for future games it develops.

This isn't the first time the publisher has turned a full-blown retail release into a limited pay-to-play multiplayer affair. Last February, Sony released Killzone 3 Multiplayer, a standalone version of the full Killzone 3 that allowed gamers to essentially sample the game's multiplayer up to a certain level cap. That game features a single $15 unlockable price tag for gamers who want to level up.

Naughty Dog's approach is much more nuanced and, the developers tell Polygon, designed to test the waters for player support of free-to-play for their titles' multiplayer.

"As a company we're looking more and more toward digital as being an interesting way to go. We're sort of testing the waters with this release."

About half a million people play Uncharted 3's multiplayer each month, said Naughty Dog game director Justin Richmond. And the team supports them with a constant stream of updates. Patch 1.17 went live on Monday.

"This is just sort of the next step in that evolution," Richmond said. "As a company we're looking more and more toward digital as being an interesting way to go. We're sort of testing the waters with this release.

"This is the first offering and we'll get fan feedback and all of that kind of stuff and it will certainly inform what we will do with our games here on out for sure."

And that means not just for Uncharted, but for all of Naughty Dog's games, including the yet-to-be-released The Last of Us.

"This isn't just an Uncharted thing or a Last of Us thing; it's sort of going forward, whatever we do," he said. "I think this is going to be a 'how it works'; there is going to be a component that is digital-only, or a component that is free-to-play ... that is something that we'll see what happens. If it's a complete disaster maybe we will rethink it. But right now we're very excited for it. I think this is something that is going to pave the way for stuff that we are thinking about for the future."

Richmond said that free-to-play was something that was always in the back of their mind when they were developing Uncharted 3, but that the game wasn't developed in a way that made that possible.

"We all thought it was a cool idea, but with a two-year production cycle it was impossible," he said. "There was no way it was going to happen."

Over the past year, the developers have been trying to figure out how to get a free-to-play version of their game's multiplayer into people's hands in the "most convenient and interesting way possible," Richmond said.

They also didn't want to screw it up, so they spent a lot of time looking at what other developers have done with free-to-play.

One of the broader questions that this experiment allows Naughty Dog to consider is whether multiplayer could be or should be sold a la carte for new game releases, instead of being included on the disc, Richmond said.

"I think that's sort of part of the larger conversations about the economics of video games, which we are very interested in, obviously," Richmond said when asked if that would be something they would consider.

While Naughty Dog remains committed to multiplayer in its games, and believes that its titles offer a form of multiplayer that other developers don't, it's also open to the idea of perhaps not including that experience on a disc after the release of The Last of Us.

"In terms of the future I think the answer is really, we don't know," he said. "The first steps toward doing any of that stuff is this experiment. Originally everything was so tied together that that would have never been an option. Now because it's been segmented out into its own thing, and that's how we're going to start building stuff from now on, then yeah, if we wanted to kick it out, if we felt like that was the right idea to kick out the multiplayer separately, we could totally do that technically.

"I don't know [if we will]. I think we'll find out a lot with this free-to-play experiment."