Megaarmor

The megaarmor (known as combat armor in the manuals) is an item that appears in the Doom games as a blue military vest (while the light armor is green and known as security armor). When collected, it increases the player's armor percentage to 200. It cannot be collected if the player already has 200 percent armor. When a megaarmor is obtained, the game displays a HUD message, Picked up the megaarmor!.

The megaarmor will absorb one half (½) of all damage received, rounded down, until it is fully depleted.

If a player that had last picked up a megaarmor is damaged to less than 100 percent armor, then they are able to pick up a green armor. If they do so, the megaarmor is replaced by the weaker armor which absorbs less damage per hit. Because of this, it is generally wise to avoid picking up green armor in this case. If the player picks up an armor bonus, however, the protection of the megaarmor will remain.

This item is not counted in the items percentage displayed at the end of each level.

Comparison with the standard armor
Since the megaarmor takes one half of all damage, the armor points are depleted at a faster rate than the standard armor, which absorbs only one third of the damage. This can be easily tried out by firing a rocket in a wall directly in front of the player. Without armor the player will take the full blast damage of 128. With the standard armor on, the armor takes one-third (⅓) of the damage, i.e. 42, and the player takes the remaining 86 points of damage. With the megaarmor on the armor absorbs 64 hit points and the player takes the remaining 64 hit points.

However, overall, a megaarmor pickup will last longer, since although it is depleted 1.5x the rate compared to standard armor, it provides 2x the number of armor points (and also provides more protection to health). Another way to view this is that (as long as the player survives) Megaarmor will only be fully destroyed after sustaining 400 damage, while standard armor will be gone after taking only 300 damage (ignoring damage number rounding from individual hits in both cases).

Appearance statistics
The IWADs contain the following numbers of megaarmors per skill level:

Doom RPG
In Doom RPG, the megaarmor is called a combat suit. It increases the player's armor rating by 50 units.