Patch 5.1 brings a number of changes to the War Event, including:

-Immune characters not receiving movement speed
-Inability to respawn on flags that are currently taken
-Reduction in immune time by 2 seconds
-Removal of drugs at the start of the event
-Losing team receiving 50% more money
-Removal of backpacks for spears and grenades
-Disablement of rolling perks during the event
-Spawning with a colt .357 or anaconda also giving healing ammo
-Leaving New Reno Wars resulting in a loss of 7 family reputation
-Shotguns on war event tier 4 or higher receiving all types of ammo
-Cost to purchase experience on gear now depends on the item tier:
tier 1: 1000
tier 2: 2500
tier 3: 6000
tier 4: 15000
tier 5: 75000
tier 6: 100000

In terms of balance, the following changes have been made:

-All heavy sniper rifles have had their ammo capacity reduced to 1
-The killing spree mechanic does not work with heavy sniper rifles
-Melee protection now also decreases weapon damage
-Slow now adds 1% attack delay per stack
-The Frozen Queen no longer requires critical hits to apply slow
-The number of Frozen Queen stacks has been changed to 5-20
-Slow protection now works against Frozen Queen and Defensive Belt
-Defensive Belt applies 10 slow to the attacker
-Fast Shot Regulator's attack delay has been changed from -50% to 35%
-Penetration protection now only works if the ammo has more than 35% penetration
-The Randomboy roll has been capped at 95%
-Sniper reload AP cost has been increased by 50%
-Killer shots from a favorite weapon give 10% lifesteal for ranged attacks
-Action Boy also gives 50 AP regen
-Bonus Battle Stats' accuracy has been changed to 50, range to 3, and damage to 15%
-Bonus HtH Attacks gives 8 turnbased attacks
-Bonus Ranged Damage lowers the target DT by 1
-Dodger's distance damage reduction has been changed to 50%
-Earlier Sequence has been changed to 30
-More Ranged Damage's damage has been changed to 5
-Sharpshooter's accuracy has been changed to double accuracy
-Priest now applies the heresy status, which sets attack delay to 1200 for 4 seconds, to anyone who attacks them
-Super Mutants also apply 10 slow to attackers

In terms of melee changes, the following adjustments have been made:
-Melee protection includes weapons stats
-Increased melee protection provided by the Firefighter(35%), WE shield(20%), Tank synergy(30%), and Iron Skin(15%)
-Decreased melee damage multipliers for swing(50%), thrust(70%), and punch(40%)
-Increased Deathclaw(10% PvE) and Soldier(1%) melee damage, as well as WE melee damage(5%), Bonus HtH Damage(5%), and Bruiser (Regulator 30%)

Other changes in Patch 5.1 include:

-Automatic deletion of main quest locations after 2 weeks of taking the quest or making progress
-Lower chance of catching raiders or bounty hunters for high reputation
-Replacement of old stealth items with new ones when a different type of stealth item is equipped

Fixes:
-Fixed Immunity on War Events
-Unlocked Hexshotting
-Fixed buying npc on war event
-Fixed Robostation robots on reroll
-Fixed Access to Fake Vault
-Fixed Sky Tower
-Fixed War Event Stats missing descriptions
-Fixed Redding contract
-Fixed Speech books cap
-Fixed real Inteligence skill cap
-Fixed -900 raider reputation Action point
-Fixed Vault contract
-Fixed gifted charisma in implant limit
-Fixed Action points on Knockout
-Fixed Marked Status
-Fixed Incinerator
-Fixed body in farm private dungeon
-Fixed Gordon Dialog
-Fixed Bass Rape
-Maps Fixes