The Hydra is a powerful asset for AI-controlled Spartans, especially in the mission Blue Team. If the player playing as John-117 or Jameson Locke finds a Hydra, they should order an AI-controlled teammate to pick it up. This is most effective for characters whose default weapons are short-ranged weapons, such as Olympia Vale or Kelly-087.
Using the Hydra near the presence of enemy Promethean Watchers is unadvisable, as they can throw Hydra missiles back at the player. If the player wants to destroy nearby Prometheans with a Hydra, they should kill the Watchers first.
It is possible to kill the Watcher with a second Hydra missile while it attempts to deflect the first missile towards the player, but this will result in the player wasting ammo.
Two Hydra missiles that directly hit will kill a Spartan, while three are required to kill with splash damage only.
If an enemy locks on to you with a Hydra, use the environment and thrust evasion maneuvers to escape.
At close range, hipfiring is more advisable.
Arena and Warzone feature two additional versions of the Hydra:
Typhon: an improved version with a faster rate of fire and lock-on time, upgraded and improved recoil compensation, higher damage output, faster reload speed, and one more additional magazine. This variant is most efficiently used for more aggressive engagements or dishing out damage to vehicles.
Echidna: an advanced version with EMP-equipped missiles, a much stronger zoom level detecting targets up to 621.79 m (2,040 ft) away, and automatic lock-on even without Smart-Link activated. This weapon can be used to facilitate boarding or hijacking action on or otherwise do great damage to enemy vehicles, and is especially useful against aerial Warzone bosses (e.g. Phaeton Helmsmen).