Gravity hammers are a class of two-handed melee weapons developed by the Covenant and inherited by its splinter factions. To their users, the Jiralhanae, they are formally designated as war hammers. The Office of Naval Intelligence has typically type-classified encountered gravity hammer variants under the designation of the Type-2 Energy Weapon/Hammer (T-2 EW/H). Nicknames for the gravity hammer includes the Hammer and the Club

A gravity hammer typically consists of a two-meter long haft, a hammerhead, and a tungsten-alloy blade on the reverse side of the head. A counterweight is attached to the bottom end of the haft. A short-range shock-field-generating gravitational energy drive is integrated inside the head of the hammer, while the head's striking face is lined with repurposed Covenant gravitic impellers, which release a concussive force upon impact. Together, the devices allows the wielder to produce an area-of-effect kinetic pulse (of approximately 4.5 meters), which briefly displaces local gravity at the point of the hammer's impact with impressive knockback. The gravitational energy drive's effects allows the user to displace objects of greater weight or power than what a normal blow might do. The gravity drive can also manipulate localized energy fields, allowing the ability to pull a target towards the wielder or push the target away. However, the Jiralhanae's brutal nature, along with the increased damage from the impellers, means that they often prefer to use the weapon in melee combat. Although humans first encountered the weapon in 2526, the exact mechanism by which the gravity hammer functions was still under investigation by United Nations Space Command in 2552.