In Doom: The Dark Ages, ammo upgrades for weapons are crucial after health and shield capacity.Ammo upgrades are scarce, making recovering or increasing ammo capacity important.To upgrade ammo capacity, collect Demonic Essence from specific leaders by defeating them.Leaders provide upgrades for types of ammo such as Shells, Cells, Spikers, Skulls, Reaver, and Launcher.Ammo upgrades in chapters like The Holy City of Aratum, The Siege, Ancestral Forge can be obtained from leaders.Chapter 10, The Forsaken Plains, offers a Skull ammo upgrade from a leader encountered after waves of enemies.In Chapter 13, From Beyond, a Reaver ammo upgrade is available after defeating an armored Mancubus.Chapter 16, The Kar’Thul Marshes, provides a Shell ammo upgrade from an armored Mancubus.Chapter 17, Temple of Lomarith, has two leaders, granting Spike and Cell ammo upgrades respectively.Lastly, in Chapter 22, Reckoning, a Cyberdemon leader offers a Launcher ammo upgrade after tough fights.