With this update, we’ve resolved an issue that halved the "hitscan range” of weapons in Halo 2 Classic multiplayer. In Halo games, the term “hitscan” refers to a projectile’s potential to instantly travel and impact its target. Several weapons in Halo 2 will use “hitscan” within given ranges, in other words they will only deal damage instantly when enemies are within a specific range. When enemies are outside of this range, the fired projectiles will need to travel over time to impact their target. This range can be referred to as a “hitscan range”.

To set the stage before diving into this fix further, it’s important to note how games update the “world state” or, in other words, how time progresses in a game. Framerate or frames per second measures how many times per second a game world is rendered, meaning how often a new image depicting the current world state is created and shown to players. Rendering is completed on a player’s console or PC and is therefore dependent on their hardware’s capabilities. Separate from the rendering of the game state, there is a “tick” that determines how often all game systems – including projectile movements – update every second. This tick functions identically for all players across all hardware configurations. For the original version of Halo 2, this tick occurred every 1/30th of a second.

When you fire a weapon in Halo 2, the next tick will capture both your weapon firing and however far the resulting projectile moved along its path within that 1/30th of a second. This is important because, in close range battles, a projectile can impact a target within its initial tick – this is the “hitscan range”. This allows your Xbox or PC to tell the game or server that it hit the target, rather than simply telling the game or server where it was aiming relative to the target. This is much more reliable at ensuring that projectiles which appear to hit on your device actually hit and deal damage in the server’s world state, and therefore deal damage on the other clients connected to the server.

How far a projectile can travel and hit an enemy within its initial tick is determined by its designer-configured projectile speed and how often the ticks occur. The faster the projectile, the longer the “hitscan range”. For example, the Battle Rifle projectile’s ‘Initial Velocity’ is 400 World Units (WU) per second so, when measured against the tick rate of 1/30th of a second, it has a “hitscan range” of 13.333 WU (133.33 feet).

To better align with framerate increases and provide a more consistent online experience, the Master Chief Collection (MCC) increased the tickrate from one tick every 1/30th of a second to one tick every 1/60th of a second. This intrinsically halves the distance a projectile travels in a single tick, which has the unintended consequence of cutting the “hitscan range” in half. Returning to the Battle Rifle example, the increased tick rate reduced the “hitscan range” from 13.333 WU (133.33 feet) to 6.667 WU (66.67 feet). In the multiplayer map Lockout, which has a length of roughly 13 WU (measured from the Sniper spawn to the Battle Rifle spawn), the legacy “hitscan range” for the Battle Rifle just barely fit but the MCC “hitscan range” was too short – until now. This update restored the Battle Rifle’s “hitscan range” to 13.333 WU, as well as restoring the “hitscan ranges” for all other affected weapons.

This difference in tickrates was also causing projectiles in the MCC version of Halo 2 to move slower overall as they were traveling only half the expected distance in each tick. This issue can be summarized as the original version of Halo 2 moving projectiles forward in time by 1/30th of a second whereas MCC moved them forward by 1/60th of a second.

Previously, some community mods have addressed this issue by increasing projectile speeds as a means of emulating the original “hitscan range”. Although this method corrects some of the issues outlined above, it may also introduce new behaviors that differ from the original release of Halo 2. The fix included in this update restores the legacy "hitscan range” and projectile speed without disrupting other sandbox behaviors.

An additional note here about this behavior across Halo titles: the “hitscan range” of the Battle Rifle has fluctuated over time. The values below illustrate the difference in “hitscan range” between each depiction of the Battle Rifle (and the DMR in Halo: Reach) in the Master Chief Collection.

• Halo 2: 13.333 WU (133.33 feet)
  
• Halo 3: 6 WU (60 feet)
  
• Halo: Reach’s DMR: 50 WU (500 feet)
  
• Halo 4: 50 WU (500 feet)
  
• Halo 2: Anniversary: 100 WU (1,000 feet)

• The Phantom Hunter Achievement can now be unlocked consistently by destroying three Phantoms during the campaign mission The Covenant
  
• Cortana narrative sequences now play as intended in the campaign mission Arrival