Lightgem
The lightgem is a light indigator on the HUD and an important part of The Dark Mod Gameplay.
The lightgem itself indicates how visible the player is. The visibility is based on how much light is hitting the player, but also depends on whether you are crouched, moving, have a weapon drawn, or being under water.
The wings on either side of the gem indicates when the player is crouching.
Below the lightgem is a health indicator. When the player is injured, a small red bar appears below the lightgem. The bar shows how much health you have left and decreases from right to left. Health potions and various types of food will replenish health. The bar remains visible until the health is fully restored.
Above the lightgem is a breath indicator. When the player is under water, a small blue bar appears above the lightgem. The bar shows how much air you have left and decreases from right to left. When the bar runs out, you'll begin to take damage. Surfacing or using a Breath Potion will restore your air bar.
The lightgem is an object that the player always carries and is not visible in the inventory.
A user can disable the lightgem and the wings in Settings - Gameplay - General - Hide Lightgem. The health indicator and breath indicator will remain visible.