From Halopedia, the Halo wiki
Spartan abilities are gameplay features in Halo 5: Guardians. They serve as a spiritual successor to armor abilities. However, unlike armor abilities, Spartan abilities are available to all players constantly, in order to guarantee fair starts to everyone. Consequently, they are comparable to previously added gameplay mechanics such as boarding or dual wielding in Halo 2 or the sprint function in Halo 4. Some Spartan abilities are the continuation of already existing gameplay features, while others make their appearance for the first time in the Halo franchise. The aim of the Spartan abilities is to portray playable Spartans as real supersoldiers with a range of powers and movement abilities that are more faithful to the Spartans' legendary lethality in the Halo universe. In the Halo sandbox, the weapon, the melee and the grenade constitute the three main layers of gameplay; the Spartan abilities are introduced as a fourth layer. The Halo 5: Guardians campaign and multiplayer have both been built around Spartan abilities. Sprint, Smart Scope, Clamber, and Slide are present in Halo Infinite, with the thruster pack being a piece of Equipment.
List of Spartan abilities
The thruster pack allows Spartans to quickly move into a chosen direction. Unlike its Halo 4 counterpart, it is a built-in feature and can be activated at anytime by the player, with a cooldown of four seconds. The acceleration is now omnidirectional and does not hinder momentum; the player can thrust into a sprint or continue their sprint at full speed. Moreover, the ability is not performed in third person view anymore, but rather in first person view. It facilitates dodging enemy fire and moving in mid-air in ways that were not possible before.
When leaping from an elevated position, Spartans can utilize their primary suit thrusters to aggressively launch a "ground pound", hammering any nearby enemies with concussive force. To activate the ground pound, the player will have to press the action button mid-air to be able to carry out this action. Before initiating the maneuver, stabilizers will momentarily engage while in air, giving time for the ability to charge and for the Spartan to aim before thrusting downwards. Ground Pound is capable of destroying damaged vehicles like the Warthog and Scorpion. Ground Pound was later used as a base reference to create the Spartan Slam ability in Halo Wars 2.
This form of attack relies on the Spartan's primary thrust component when engaging in close quarters combat. The ability requires the Spartan to sprint at top speed before running headlong at an enemy combatant. The Spartan will execute a shoulder bash, which will deal slightly more damage and knockback than the typical melee attack. Similar to melee attacks, a Spartan Charge to the back of an enemy will result in an instant kill.
The agility of the MJOLNIR armor systems allows Spartans to traverse any terrain with ease. Spartans can now grab ledges and clamber over them with enhanced mobility and flexibility. This allows them to make jumps that were once impossible without tricks used in previous games.
Once Spartans reach top sprinting speed, joint actuators will engage to give them the ability to slide a short distance in order to evade incoming enemy fire or danger.
Software in MJOLNIR armor systems allow Spartans to increase accuracy via their smart-linked weapon system through their suit's heads-up display. Weapons, such as the MA5D assault rifle or M6H2 magnum, feature an enhanced, holographic zoom for steady accuracy.
Activating the Smart Scope in midair will also allow Spartans to briefly hover in place with their thruster pack while aiming.(Stabilizer)
Using the Smart Scope in midair will activate the thrusters, allowing a Spartan to temporarily hover midair for a few seconds while aiming.
Sprint allows the Spartan to move at an increased speed. Unlike in Halo: Reach and Halo 4, sprinting resets the duration of time before the player's energy shields begin to recharge, although this effect is only present in multiplayer. Prolonged sprinting will activate the thrusters to reach top speed, which allows Spartan Charge or Slide to be used. In addition, should the player take damage while sprinting before reaching top speed, they will automatically stop sprinting.
Spartan abilities can be used successively to "chain" abilities. This can be useful for performing "trick jumps" to take alternate paths around the map.