Call of Duty: Modern Warfare 4 Launch Patch Notes — Every Weapon, Movement and Balance Change Explained

Call of Duty: Modern Warfare 4 officially launches on October 23, and Infinity Ward used the day before release to publish a full set of launch patch notes covering everything that changed since the public Beta. The notes cover weapon balance, movement, spawns, killstreaks, Perks and a long list of DMZ bug fixes, and together they're the clearest picture yet of what the finished game plays like compared to what Beta testers tried over the summer.

Here's a breakdown of the day-one changes that matter most, drawn directly from Infinity Ward's own patch notes.

1. Launch Day, By the Numbers

Modern Warfare 4 is led by Infinity Ward, with Beenox, Digital Legends, Activision Shanghai, Raven Software, Treyarch, Sledgehammer Games and High Moon Studios all contributing, and it's published by Activision. The campaign is set on the Korean Peninsula, where a North Korean invasion threatens to destabilize the world, continuing the rebooted Modern Warfare storyline Infinity Ward has built since 2019. For anyone catching up before launch, the campaign's biggest twists heading into launch are worth a read first.

At launch, the game ships with 20 Multiplayer maps (12 Core 6v6 maps, three Ground War maps, four Gunfight maps, plus the dynamic Kill Block), over a dozen Multiplayer modes, 33 weapons, 33 Operators and a progression system that runs through Level 55 and beyond. DMZ's Hajin Forward Operating Base is also live at launch alongside the full Campaign.

2. Every Map and Mode Available on Day One

The full launch map list spans Core 6v6 (Cachette, Coal, Lithium, Lotus, Mumbai, Munition, Nautical, Reactor, U92, Rooftops, Sentry, Silkworm, Transit 213), three Ground War 32v32 maps (Imjin Farmland, Wolves Stadium, Forest) and four Gunfight 2v2 maps (Cafe, Library, NYC, Smuggler), plus Kill Block, a new dynamic map that supports 3v3 and 10v10 Gunfight at launch with 6v6 support and new layouts promised post-launch. For the complete rundown of every mode and the new Ballistic Authority gunplay system, the full confirmed map and mode lineup covers it in more depth.

Returning classics like TDM, Domination, Hardpoint, Kill Confirmed, Free-For-All, Frontline, Search & Destroy and Gun Game are joined by four brand-new modes at launch: Inflation (eliminate enemies and collect their cash, with High Value Targets revealed to both teams once they carry enough), Hijack (fight for a Data Spike and carry it to the enemy Comm Station to score), Collateral (a round-based Search & Destroy hybrid with a Buy Phase, starting each round with a pistol and $800) and Combat Outpost (a Ground War mode built around capturing and reinforcing territory). Infected and a new mode called Possession are scheduled to drop the following week as a Halloween event.

3. Weapon Tuning and the Gunsmith Overhaul

The biggest swing in the patch notes is time-to-kill. Infinity Ward says Beta Weekend 2's faster-paced TTK was "strongly preferred by all skill levels" over Weekend 1, but the team admits it didn't get weapon-to-weapon balance exactly right in that build. For launch, SMGs have been made more efficient at close-to-mid range, and one-hit-kill weapons have had their flinch and damage tuning adjusted so they're no longer an automatic best pick. The studio frames its approach around three "weapon pillars": Distinction (each class has a clear role), Balance (every tool can find success) and Feel.

Gunsmith itself has also changed. A new Optic Rail Placement feature lets players fine-tune their ADS sight picture, Reticle Customization now changes the visual effect of thermal optics, and Advanced Weapon Stats are available to everyone from day one. Weapon progression has been streamlined around shared attachments that unlock across a player's whole arsenal at once, and Weapon Prestige returns for players who want a deeper, dedicated grind on a single gun. All 33 launch weapons are split across Assault Rifles, SMGs, Shotguns, LMGs, Marksman Rifles, Sniper Rifles, Pistols, Launchers and Melee.

4. Progression, Prestige and Killstreak Changes

For the first time in a Modern Warfare game, there are two separate Prestige paths to choose from, each unlocking its own Operator Skins and Weapon Blueprints as players climb through ten Prestige icons. Players who reach Prestige Master and Prestige Legend get icons that honor the series' history, and a full set of legacy Prestige icons from past Modern Warfare games is available for returning veterans. The Weapon Camo grind is shared across Multiplayer, DMZ and, once Season 1 begins, Call of Duty: Warzone, with Special Camo Challenges automatically adapting to whichever mode is being played.

Killstreaks have also shifted since the Beta. Modern Warfare 4 launches with 17 Killstreaks, usable on individual loadouts for the first time in the sub-series, backed by a new Smart Streak Meter that credits objective play toward a player's next streak. The Beta's cost increase for all streaks carries over to launch, meaning a UAV costs five kills (four with the Hardline Perk). Two further adjustments landed specifically for launch: UAV health has been raised from 100 to 150 after Beta feedback said they died too easily, and the Wheelson's AI pathing and targeting have been reworked to be more aggressive.

5. Movement, Spawns and Perk Tuning From Beta Feedback

Infinity Ward says it spent the post-Beta window smoothing the transitions between movement actions so they "feel grounded" with a clear cost for a clear benefit. The team also fixed bugs where enemy movement didn't match between first- and third-person views, which had been creating unrealistic-looking motion and unintended "snaking" exploits. Tactical Sprint remains off by default, as it was in the Beta; it's tied to the Blood Rush Perk, now slotted into Perk 2, and its default input is a single tap of the sprint button rather than a double tap.

Spawn logic has kept iterating too, with further work on player separation, squad spawning and Hardpoint spawn predictability aimed at keeping players close to the action without feeling dropped into the enemy's lap. Perk distribution was also rebalanced across all three tiers, and several individual Perks were buffed for launch: Battle Hardened now better resists Flash, Concussion and Screamer Mine effects, Resupply's first recharge comes faster, and Blood Rush now triggers Tactical Sprint automatically when a player sprints, with a manual override available in the movement settings for anyone who prefers to control it directly.

6. DMZ's Rolling Hotfixes, Pre-Load and What's Coming Next

DMZ got two rounds of fixes in the final run-up to launch, dated October 20 and October 21 in the official notes. They address a crash when breaching the door in the Breaking New Ground mission, an After-Action Report bug that could show 0 XP after a player's first match, a non-functional ISO Apex Attachment, double completion credit on story missions, enemy AI running over downed players, keypad codes spawning in locked rooms, players getting stuck in rocks around Hajin, and a soft-lock that could occur when selling starting equipment before a player's first deployment. Nintendo Switch 2 got two specific fixes: a blocked progression prompt in the Chemical Denial Dynamic Op at NuriGO Mall, and an issue preventing players from purchasing saved Blueprint modifications. For more on how the Switch 2 version is shaping up more broadly, how the game performs on Switch 2 digs into that separately, and the DMZ fixes sit on top of the systems covered in Hajin and the DMZ Forward Operating Base.

On the Campaign side, Infinity Ward fixed a progression blocker in the Hotel sequence of the Counter Attack mission, and on the weapons front, a bug that showed a 0.00 TTK for the Rezi 12 Shotgun on the Firing Range is now resolved. Pre-installation began rolling out on October 14 at 9 PM PT, according to the official @CODUpdates account, and lets players choose what to download, including whether to install Warzone alongside Modern Warfare 4 (the current live version installs until the new Warzone arrives with Season 1). Players on platforms with automatic downloads, like PS5, should disable that setting beforehand if they want control over what gets installed first.

Infinity Ward is also changing its live-service cadence: Weekly Challenges won't be part of Season 1, replaced by a mix of new and returning Events with rewards like Apex Attachments, Weapon Camos, Calling Cards and Operator Skins, including recurring Events for anyone who misses a full track the first time. The first Event kicks off on launch day itself. The studio is tracking ongoing issues on its official Modern Warfare 4 Trello board and posting updates through the @CODUpdates account on social media.

Quick-Tips Recap

• Modern Warfare 4 launches October 23 with 20 Multiplayer maps, 33 weapons, 33 Operators and DMZ's Hajin Forward Operating Base.
• Expect a faster TTK than Beta Weekend 1, with SMGs buffed at close range and one-hit-kill weapons tuned down via flinch and damage changes.
• Tactical Sprint is off by default; equip the Blood Rush Perk (now Perk 2) if you want it, and set it to single-tap, double-tap or automatic in the movement settings.
• UAVs now have 150 health instead of 100, and cost five kills (four with Hardline).
• Switch 2 players got two targeted DMZ fixes in this patch; check installation settings before launch if you're on a platform with automatic downloads.
• Weekly Challenges are gone for Season 1, replaced by recurring Events starting on day one.

Official Resources

• Call of Duty: Modern Warfare 4 Launch Patch Notes (Infinity Ward, official)
• Call of Duty: Modern Warfare 4 official site
• Call of Duty: Modern Warfare 4 on Steam

Check back on our full walkthroughs archive as more Modern Warfare 4 coverage lands through launch week.