Details on Dark Souls III have, apparently, been leaked. The leaked info was obtained by The Know, a news show on YouTube for Rooster Teeth. As well as leaked details, The Know, also acquired 19 screenshots and concept art for the game.
How The Know obtained this information was not revealed. All they stated was that it came form an "anonymous source". From Software also has yet to comment on this supposed leak.
Until official confirmation from From Software themselves, this information should be taken with a grain of salt (though it seems very likely).
The alleged release window for Dark Souls III is 2016 on PlayStation 4 and Xbox One. A PC port has been stated as being "negotiable". According to the leak, the player count will be 1 - 4. Though whether or not this player count is for co-op or PVP has yet to be revealed.
It is also said that there will be 10 playable classes, all of which will be available from the start. There will also be 45 new enemies and 15 new bosses. The Know go on further to state that characters and enemies from the previous games are not counted in those numbers. The same goes for weapons and armor.
Supposedly, there will also be 100 new weapons, 40 new armor sets, and 200 new items. Dark Souls III will also feature 60 minutes of cutscenes, most of which will be in-engine. This is something especially new to the Souls series and Bloodborne.
Bosses in the game will also "Heat Up" due to "undescribed factors". This will more than likely make the boss even harder to beat.
To join another player's game you will have to drag a body around and perform a "sacrificial ceremony", but this will mark you and make you a target for other players in that game. These "sacrificial ceremonies" can also create a new bonfire to rest at or have other players join your game.
Dark Souls III is also said to feature around 12 areas, The Know state that this is to make it more akin to the original Dark Souls. The game will also feature "Sword Fighting Arts". Not much is said on this feature, but it sounds to be special fighting moves your character will be able to do after you choose them. Two other features will be "Rush in" and "Circle". Rush in will allow the player to dive into a fight and take damage, but deal a tremendous blow to the enemy. Circle sounds to be a dodge move, but it also said to be a retreating move to get away from a fight.
The final piece of information from this anonymous source is that Dark Souls III will debut at E3 2015. So keep your eyes peeled.
Like previously stated, until all of this information is officially confirmed by From Software themselves, this should all be taken with a grain of salt. Though all of the information and screenshots do seem legit. You can find The Know's YouTube video breaking the news here.
Have a lovely day :).