The gameplay in Dark revolves around stealth combat, where the less you're seen, the better you'll do. Sanctuary acts like a hub in the game, where you will be given missions and hang out with some of the characters from the game. The game appears to adopt a mission-based system, where you will return to Sanctuary in between each mission.
While the game emphasizes stealth, players can do more than just that, as they can charge in and attack foes head-on. Eric Bane's health and special powers are linked, meaning that if you use a skill that uses your special, your health will decrease. Although some skills don't use these blood points, if you do use them all, then you will be just a sliver of health away from death.
As you're moving around during the missions, enemies might spot you, which is shown as the circle appearing on the screen. If it turns completely red, that means the enemy has spotted you and will be aggressive in trying to hunt you down. Enemies will also become aggressive if they spot any dead bodies laying around, which means it is imperative to hide them behind other objects if you're playing stealthily.
There will be two different ways to take out foes, with each one providing a different result. The stealth kill is quick and silent, but doesn't benefit you in any other way than killing that enemy without alerting others. The other method of killing someone is by biting them, which is slower than using stealth and can cause noise. Killing this way will replenish a blood point.