Microsoft's PC and Xbox One multiplayer-focused, four-versus-one cross-platform role-playing game Fable Legends is free-to-play.

Fable Legends is developer Lionhead's first free-to-play game, and marks a significant departure from previous entries in the series not only in terms of gameplay, but how customers will pay for it.

Much like Riot with its hugely successful MOBA League of Legends, Lionhead will rotate the heroes that will be available to play for free in Fable Legends, but also let players unlock them for permanent use by spending the in-game currency or real world money.

Here's how it works: at launch Fable Legends will offer four different heroes to play for free. After two weeks these four heroes will leave the rotation and be replaced by a new group of heroes. This process will continue for as long as Microsoft's servers run the game.

If you want to unlock a hero so you can play it whenever you want, you can spend silver coins, the in-game currency gained through playing quests, or buy it with real world money. Your hero and equipment progress is maintained throughout. Lionhead is yet to decide how much heroes will cost to buy.

For those who prefer to play as the villain, which involves a top-down camera perspective and a more real-time strategy, dungeon master style of gameplay, you can buy creatures.

As the villain, you'll play through the story arc just like hero players do. Each quest includes creatures that are native to that quest, and you can use these for free, forever. However, if you return to that quest but want to use non-native creatures in it, you need to unlock them with the silver you've earned or real money. Traps, gates and standing stones (the latter of which grant area of effect health), can also be unlocked with silver or bought with real money.

Dotted around quest maps are chests, which come in three tiers, each guaranteeing a specific quality of randomised items. Inside chests you'll find weapons, augments, armour, items, potions and silver. You'll run into these during gameplay, but you can also buy them, back in town, using silver or real money.

Lionhead plans to add new heroes, creatures, quests and arch villains to Fable Legends in seasons. Story wise, it's going for a Telltale-style episodic structure. It's already building content to be added beyond season one, and hopes to support the game for years.

Expanding to PC, enabling cross-platform play with the Xbox One version and going free-to-play is in part an attempt to grow the audience for the Fable series, Lionhead said in a presentation held earlier this week at its offices in Guildford, but it's also a bid to replicate the huge success of free-to-play games such as League of Legends.

"There's no denying the similarities there," studio head John Needham tells Eurogamer in an interview.

"We all play League of Legends. I've spent a good year-and-a-half of my life hard playing League of Legends and love it. So there's no denying that was the big inspiration of ours."

Free-to-play has a troubled reputation, especially among core gamers, but it's a business model that works well for Riot, as well as Blizzard with virtual card game Hearthstone, and Valve with the likes of Team Fortress 2 and Dota 2.

These games make huge amounts of money while keeping their players happy because they're considered to be balanced. And that's exactly what Lionhead is going for with Fable Legends.

"There are free-to-play games like World of Tanks out there that are very much a pay-to-win kind of experience," game director David Eckelberry tells Eurogamer.

"For me the better ones for the customers are the ones where you get to enjoy all of the content without paying money. And then you pay if you want to.

"Our mission is for a fun experience on any platform. As a first-party studio our goal isn't to invoke anything vaguely like buyers remorse. I want my players to feel like, oh, I bought something cool. I don't regret that purchase. That's what matters to me.

"When I've played my 30th hour of Hearthstone, at some point I decided, I should probably give Blizzard some money. I felt like I owed them something because they'd made such a great game for me to play, and I didn't need to spend money in the game, but I thought I should. So I bought some card packs. I did the same thing in Team Fortress and eventually in League of Legends.

"That's the kind of feeling I want to invoke with our players. I want them to have such a fun experience that some percentage of them go, okay I'm going to buy a hero that just came out, or I'll get Winter a new hairstyle and a cool-looking hood. That's the kind of feeling we want to generate in our players where, we've offered them such a good time that they're spending time in it that they feel valuable."

Malice is a heavily-armoured warlord brought back from the dead and forced to repent for his sins. His role in combat is as an offensive tank who creates minions out of dead enemies.

For many of us, the phrase "free-to-play" sparks concern about the prospect of death grinds, energy timers and disheartening design that tries to get you to buy gems every few minutes. Lionhead says it hopes Fable Legends will be "fair" and "generous", and to this end everything in the game that affects gameplay can be earned for free. None of the quests (season one includes between 12 and 15 designed to fit into a cohesive narrative arc) are behind a pay wall. The only barrier to playing quest nine, for example, is completing quest eight. You can't buy experience points, high level characters or abilities, either. These must be earned through normal gameplay.

But you can buy heroes, although the patient may not have to. Eckelberry estimates it'll take around a fortnight to gain enough silver through gameplay to buy a hero, which fits in with the plan of rotating the heroes that are freely available every couple of weeks. Eckelberry is pretty up front about the prospect of the business model in our interview:

I imagine there's going to be a mixed reaction. There are players out there who don't like free-to-play, and I get that. it's got a mixed reputation. There have been games that are respectful and fair, and there have been things that aren't. I can't blame people for having a mixed reaction to that. The only thing I can say about it is, look, you can believe what you want, but if you want to download the game and give it a try you can do that. You could play it for one night and say, oh, this isn't the game for me, or fall in love with it. Word of mouth is going to be more important than anything - allowing people to play it as they want, then someone in your friends group is playing it, and if they're having a fun time with it, and they're like, no I don't get pushed, they're not poking me every 30 seconds to buy something, it's just a fun game that happens to be free-to-play, that's where I'm going. Am I nervous about the news? Sure, a little. We're going to get some negative hate mail. Do I think it is the best proposition we can make for our gamers? I do. Or else I wouldn't be here. I like this project, and the last thing I want to do is attach a poison pill to it. Microsoft isn't about extracting the last nickel of players, or something silly like that. We want to create a great community of players that is playing for a long period of time. That doesn't work if you buy something and regret it a day later. That just doesn't make any sense. Even though most of our players will never pay anything, that's still immensely valuable to us to have players playing on Windows 10 and Xbox One. It shows off the strengths of our platforms and the strength of our gaming audience, the bigger we grow it. It's the luxury of first-party.

Eyebrows will be raised, however, by Fable Legends' chest system. While you'll find chests while out on quests, and earn silver coins through normal gameplay to buy chests back at the city of Brightlodge, you will be able to buy them with real world money, too. And given chests include items such as weapons, armour, potions and augments, some will be concerned that Lionhead may teeter across the line into troubled pay-to-win territory.

Eckelberry counters this concern by saying Fable Legends is designed to encourage players to seek out chests found only through questing. Some chests in the game world offer a better chance of containing a specific, coveted item players may want, so players will want to return to the quest in which they are found in the hope that item will drop. This won't be true for the chests available to buy back in Brightlodge, which runs a more generic treasure pool.

Eckelberry adds that Fable Legends has been designed to allow heroes of variable level to play with each other. The game prioritises class roles over hero level, he said. For example, a max level Leech (a healing hero), even with the best gear in the game, will never be a better tank than Inga.

"We're not looking at an unbalanced game, regardless of how you got the treasure," Eckelberry says. "So whether you bought it to get the different outfits and looks and stats, or you've earned it by just going up to the treasure chest and opening it, it's not going to be game-breaking in either sense."

It's also important to note that the game prevents players from buying items during gameplay. So, you won't be able to buy potions or augments in the middle of a quest if you're running low or looking like you'll lose, for example. And, items are tied to your hero's level. So, your low level hero can't equip a high level weapon, for example.

10 heroes have been revealed so far. Four more are currently in development and due out this year.

While Lionhead insists it's going for a fair and generous business model for Fable Legends, there is a school of thought that free-to-play always affects game design. That is, it's impossible to avoid having to tweak your game to accommodate free-to-play.

In some free-to-play games, this manifests itself in a negative way, with progress timers, energy gates and grinding that force you to pay to progress. After all, with free-to-play there must be some reason for at least a small percentage of players to pay, otherwise no money would be made.

Eckelberry admits Lionhead had to adjust its production plan in order to facilitate Fable Legends being a free-to-play game, but insists that was more about adding additional content than adjusting design.

We probably made a few more heroes than we would have made, because we think that's the coolest thing probably to buy in our game. We maybe would have stopped at eight heroes, instead of more than a dozen we're going to release with. And we probably couldn't keep making them forever if someone wasn't willing to buy them. But we'll find out. How often do players want more heroes and how much do they love them? It's the same with creatures on villain side. Who cares what the business model is if the game is no fun? The only way it's really affected us is, if we were not free-to-play in the slightest, we could have released a little earlier in some ways. From a narrative point of view, we want to have enough quests and story that it feels like a good amount of narrative and content that, in theory, we could have charged $60 for. There are enough hours of gameplay just playing the quests through from start to finish. We're not a five hour experience. We're more than that, to say nothing of the multiplication of doing different heroes and villains. Then we kept building new quests that will take us past the first season. We're starting to make heroes that will take us past the first release date. It's not clear we would be doing exactly that.

Fable Legends is currently in closed beta, where it will remain for at least the next few months as the free-to-play business model is added to the game. Lionhead will then gauge reaction and adjust accordingly, studio head John Needham adds.

"We're already starting an open dialogue with our beta community on the strengths of the game. That will extend out when we start introducing how we're going to do monetisation in the game to that conversation in beta. We'll have a transparent dialogue with our community."

Speaking with a number of people at Lionhead about the decision to go free-to-play with Fable Legends, I hear the phrase "natural choice" over and over again. Free-to-play might have been the "natural choice" for Fable Legends, but I also wonder whether it was the only one.

It's no secret that Lionhead has struggled to explain the concept of Fable Legends. It's been hard to work out how the four-versus-one gameplay would fit in with the traditional RPG mechanics and sweeping story of past Fable games. Lionhead insists Fable Legends has a story, an emote wheel and, yes, you can fart on villagers, but it's clear the focus is on multiplayer, and for many Fable veterans, that's off-putting.

"We've been out there talking about the game for more than a year now, but a lot of fans have trouble understanding what a 4v1 is," Eckelberry admits.

"Can we tell story through this? How do we do episodic structure? The honest answer is, it is so new that we struggle to deliver that message. The way we've proven time and time again in the last year, since E3, about how we get people to understand what the game is and fall in love with it as much as we've fallen in love with it, the answer is just for them to play it.

"If you're not sure about Fable Legends, and you're not sure it's the game for you because it's got some big differences from previous Fable games, the ultimate answer for us was just to put it out there and let the world play it."

Microsoft and Lionhead will be hoping at least a few people pay for it, too.