During the Modern Warfare 4 Beta, in August and September 2026, Infinity Ward kept a change diary on the official site: the "Call of Duty: Modern Warfare 4 Beta Patch Notes", last updated on September 1, 2026. This article, written by the SequeLariCOD team in our own words, sums up what changed from one day to the next and what the studio said it would keep tuning until launch. The Beta is over and the final game came out on October 23, 2026, so the Beta values no longer apply to today's game: for current changes, see the launch and Season 1 patch notes.
August 28: the Open Beta starts with big changes
On the first day of the Open Beta, the notes bring the longest list of changes. Every weapon was tuned so players could take a few more shots, without making weapons weak at range. Spawns got more separation between teams, and Hardpoint became less predictable. For movement, Tactical Sprint stopped being default and moved to the Blood Rush perk; slide distance dropped 10% and slide speed 9%. Aim assist was reduced for everyone, Warzone included, and the studio warned that it was not the final tuning yet.
- Killstreaks: all of them cost one more elimination, and the UAV got 60% less health.
- Score: Team Deathmatch went from 75 to 100 points and Kill Confirmed from 65 to 75.
- New content: the Lithium map, the Hijack mode, Resurgence Quads on Zodiac and the level 30 cap.
- PC: better performance and fewer hitches, plus the reminder that RICOCHET anti-cheat requires TPM 2.0 and Secure Boot enabled.
August 29 and 30: Ground War, Warzone and double XP
On August 29, Wolves Stadium and Imjin Farmlands arrived in Ground War, in the Combat Outpost format. Weapons changed little, but those with fewer than 60 reserve rounds got an extra magazine. In Warzone, players could revive a teammate while prone, the Sang 9mm became the infil and backup pistol, sprinting with a weapon got slightly faster, and multiple UAVs no longer combined into an Advanced UAV. There was also a new option to reduce first-person camera movement, useful for players who feel sick from screen motion.
On August 30, double XP (player and weapon) started and Transit 213 24/7 was added. On that map, the Team Deathmatch score went from 100 to 150 and Kill Confirmed from 75 to 100. In Warzone, HUD shake was turned off for the Open Beta and the blood and Death's Door effects were adjusted.
August 31: weapons and Zodiac visuals
On the last full day, the notes bring another weapon pass, with damage and range numbers for several of them, such as the Han 86, ISO Nightshade, Type 73, FiNN LMG, Oris 8.6 and Krait P68, plus Rezi 12 attachments. We deliberately do not repeat those numbers here: they were Beta values and changed again at launch. In Warzone, the Zodiac map became easier to see, with less excessive bloom, better visibility into and out of buildings and brighter character outlines; the sound of enemies using the Ascender and landing with a parachute became easier to hear.
Zodiac, the Resurgence map
In the August 27 preview, the notes introduce Zodiac: a Resurgence map in South Korea, inside the MW4 setting, built by the team behind Rebirth Island and Vondel, with 10 points of interest, including Old Mine, Solar, Trackline and the sewers. In the Beta it had Resurgence Quads and Casual Quads. For today's Zodiac, see the map page and our Warzone Season 1 guide.
September 1: the end and the next steps
On the last day, Infinity Ward thanked players and listed what it would keep working on until launch. In multiplayer: time to kill and weapon tuning, perks so the choices matter more, further aim assist changes, spawns and Nintendo Switch 2 performance. In Warzone: interface readability, audio (especially footsteps), movement feel and map pacing.
A date detail: according to these notes, the Beta ended at 10 PM Pacific on September 1, which is 2 AM on September 2 in Brasília. The August post about the Beta said 10 AM Pacific. Since the notes are from that same day and from the studio, they look like the most recent notice, but we record both versions instead of picking one by guesswork.
What the notes do not say
The notes also list Early Access entries, from August 20 to 25, but their text was not available when we checked, so they are left out. We do not know how much of each Beta change was kept in the final game: the notes only say what the studio intended. And, as always, no programs that "improve aim" or promise an edge: that is cheating, leads to bans and is often a scam. See our Play safe page.