Normal difficultly levelsEdit
By default, 3 difficulty levels are accessible from the start of the game: Casual, Normal and Hard. Each level increases the threat level of enemies and decreases the availability of supplies.
New Game+ difficulty levels/modesEdit
After completing the game at least once on any available difficulty, another, harder skill level becomes available. Several different playmodes are also unlocked and can be accessed at the New Game+ menu at the main menu screen.
By far the (default) most difficult skill level playable in-game. Ammunition and resources becomes vastly more scarce compared to lower difficulties, Necromorphs can now withstand much more punishment than before.
Completing Impossible mode grants +3DMG Circuits which can be used in crafting.
This allows you to start a new game with all of the inventory, weapons and suits from a previous save, this can be played at any normal difficulty level.
In Classic Mode, co-op play is removed, crafting is also unavailable. The player is restricted to building only weapons available in previous games from blue prints. This mode also features 'classic aiming' and a reduced number of inventory slots to begin with, which increases as the player acquires new RIG suits. The skill level for Classic is set to Hard.
Finishing this mode unlocks the Devil Horns.
The Classic mode also unlocks the Hostile environment suit on completion.
This mode has its difficulty level set to Hard.
The Hardcore Mode of Dead Space 3 is vastly different from that of Dead Space 2. The player must begin a fresh game on Hard difficulty level. Unlike in Dead Space 2, saves are not restricted as all manual savings have been removed, instead dying on Hard Core forces the player to start the ENTIRE game over.
Clearing Hardcore Mode unlocks the Retro graphics setting.
Retro mode, unlike the name suggests, is merely a change in graphics quality of the game, nothing is altered from the stock gameplay. The Retro setting is accesed via the Options menu.