It's hard to say where the gaming industry is heading, but freemium games are likely playing a big part in it. Where traditional games ask for your sixty dollars up front, freemium games take their cut through micro-payment, and advertising systems. It's shown to be a popular business model, and although the overall quality of these games is not always on par with their big-budget counterparts, they're quickly catching up.

Naturally, traditional gaming studios want a piece of the pie. A number of big names have already tried their hand at cheap, or free to play titles, but another interesting trend is the transition of previously premium games to the freemium model. And it's a smart move. High-quality games that are reaching the end of their premium lives can find a new home, and reach a new audience as free-to-play games.

Below are five online multiplayer games that started out as premium games, but are currently now free premium online games.

Team Fortress 2

Developed by Valve, the same gaming studio that brought us Half Life and Counter-Strike, comes Team Fortress 2. It's a fast-paced MMO action game, notable for its cartoony looks and hilariously over the top situations. Also, hats.

In the game, you join one of the two teams as a Pyro, Engineer, Spy, Heavy, Sniper, Scout, Soldier, Demoman, or Medic and play through classic game modes like capture the flag, control point, escort missions, and arena games (which boil down to team deathmatches).

free premium online games

Team Fortress 2 was originally released for the computer in 2007, with console versions to follow, and received much critical acclaim. Approximately one year ago, in June 2011, the game was made free-to-play, with a micro-transaction system for hats and other useful in-game items.

Although there are no subscriptions, a distinction is still made between free and premium accounts, mostly through inventory size and item availability. The premium account status is given to those players that have ever spent any money on the game; by paying for it in the past, or by purchasing items in the in-game store. View a comparison of the free and premium accounts here.

The Lord of the Rings Online

Set in the realm of middle-earth, this famous MMORPG gives you an active role in the enchanting world of Tolkien. The game takes place during the time period of the like-named books and movies, and you'll stumble upon a number of familiar characters during the game.

free premium games

The gameplay is focused around character development mainly through Player versus Environment combat and storyline questing, but offers ample opportunity for Player versus Player combat through the Monster Play mode, where fights are waged to gain control over various keeps.

The game was made free-to-play late 2010, with an optional subscription model. The main restriction in the free mode is the number of available quest packs. Although this poses no problem when you're starting out, you'll likely reach a point where further character development requires the purchase of additional quest packs. A full comparison of the game modes can be found here.

Aion Online

Aion Online is another popular MMORPG in a beautiful fantasy setting, where two powerful factions of winged characters are pitted against each other. Aion employs a class-based character system, and leaves ample room for both PvE and PvP adventures. This standard MMO setting is spiced up with a combat-system that allows you to chain attacks, and (hold on to your hats) airborne combat.

free premium games

While the European version of Aion technically moved to a free-to-play model earlier this year, the gameplay was heavily restricted. Now, the American counterpart is heading down the freemium road as well, and without the European version's plethora of restrictions!

EverQuest II

Even if you haven't played this games, chances are you've heard about it. EverQuest II is an MMORPG in a fantasy setting, situated on the world of Norrath. The gameplay is class-based, and largely oriented at PvE (player versus environment), although there is also opportunity for PvP (player versus player).

free premium games

EverQuest II is by no means a new game. It was originally released back in 2004, but expansion packs have been hitting the shelves up to last year. The game transitioned from its subscription model to a free-to-play model with some feature restrictions, and an optional subscription plan. Take a look at the feature comparison for more information.

DC Universe Online

This one is a great game for all the comic book nerds out there. Rather than play a paladin in a fantasy setting, you can get into the skin of a superhero, or a super villain in the DC Universe. Most of the focus lies on player versus environment gameplay, where you can fight solo, or in a team.

This is supplemented with a fair amount of PvP play. 'Legends' are queued instance encounters where players take charge of famous DC avatars, but players can also use their own characters in the Arena, and during large-scale raids.

free premium online games

The game turned free earlier this year, with an optional premium plan. The biggest restrictions are in terms of inventory caps, available content, and trading mechanics. View the full comparison of the different plans here.

Have you played any of the games on this list? Let us know what you thought about it in the comments below!