This article is about the Real World
Gears of War doesn't have a traditional health bar, nor does it have health packs or first aid kits that you must find in order to heal your player. Instead, the Crimson Omen appears in the center of the screen, and alerts players that their character is suffering damage. The Gear's shading gets more and more intense as the character continues to take damage until it is fully red. Depending on the difficulty and game type, a fully red Omen either downs the player, or outright kills them. Taking Cover, fleeing the action, or neutralizing any threats are all viable ways to limit damage. Once the character stops taking damage, the red omen fades just as gradually as it appears, and the character eventually returns to full health.
If the Gear becomes fully red and the player gets downed in a single player game, the mission is considered failed and the player has to restart. In a Co-Op game, a player can revive his downed partner unless they are taking separate paths.
Note that in Casual or Normal in Gears of War 2, players who get downed in single player will be down and can be revived by nearby AI teammates. Also, in co-op, players can be revived by AI teammates even in instances where both players are taking separate paths.