Field Upgrades are a game mechanic featured in Battlefield 4. Functioning in a similar manner to the Specializations of Battlefield 3, these grant additional abilities to players.
Field Upgrades function in a similar manner to Battlefield 2142. There are 29 different field upgrades available for use when choosing from the 11 available Upgrade Paths (short for Field Upgrade Path). Each path holds up to four different field upgrades that are obtained by progress chained by squad-based team work. There are a total of eleven upgrade paths, with three paths available for all classes and two paths unique to each class.
Paths can be freely chosen anytime during matches with progress for each path saved whenever a new path is chosen, a kit has been changed, or a new squad has been joined. Some progress, however, is lost for the path currently in use whenever the player and their squad have been wiped. Progress does not carry over to consecutive matches.
Three of these field upgrades are initially locked. As the squad completes objectives, or the squad is granted a promotion by the commander, the remaining field upgrades are unlocked and stack. Some of these objectives are as follows:
Repairing vehicles occupied by squad mates
Resupplying squad mates
Healing squad mates
Spawning on squad mates
Competing objectives given by the squad leader
Saving or avenging squad mates from enemies
If every member of a squad is dead or has yet to deploy, the squad loses the use of one field upgrade each time this occurs. This system replaces the collaborative system in Battlefield 3 and the potential waste if squadmates selected the same specialization.
Increases maximum amount of ammunition held by 50% to 100% depending on the weapon being used. (This only affects all three M82A3 variants, all three AMR-2 variants, both USAS-12 variants, the M60-ULT and the Rorsch Mk-1.)
Offensive - Tier 2
Indirect Fire - Tier 2
Perimeter Defense - Tier 1
Increases the maximum number of Grenades held by one.
Offensive - Tier 3
Grenadier - Tier 1
Increases the height a player is able to fall before sustaining damage. Only works at certain height thresholds such as that similar to a two-story building.
Offensive - Tier 4
Shadow - Tier 3
Reduces incoming damage taken to the torso by 10%. Requires most primary weapons to fire an extra bullet in order in order to kill players with ARMOR equipped. Also prevents standard sniper rifles from earning close-range kills to the chest.
Defensive - Tier 1
Decreases the amount of incoming suppressive fire by 50%.
Defensive - Tier 2
Mechanic - Tier 3
Sniper - Tier 2
Decreases damage from explosives by 15%. Does not protect against direct hits from explosives.
Defensive - Tier 3
Grenadier - Tier 4
Mechanic - Tier 2
Anti-Tank - Tier 4
Decreases the amount of time it takes to start regenerating health by 20%.
Defensive - Tier 4
Reduces the amount of time a player is spotted when they move out of their spotters sight from seven seconds to five seconds.
Shadow - Tier 1
Spec Ops - Tier 4
Sniper - Tier 3
Causes players to be undetectable to the MTN-55 and T-UGS except when sprinting.
Increases the maximum number of M18 Claymores able to be held to three.
Perimeter Defense - Tier 3
Increases the number of times the MP-APS can deflect incoming explosives before getting destroyed.
Perimeter Defense - Tier 4
Increases the maximum amount of C4 able to be held to six. All six can be deployed at once.
Spec Ops - Tier 2
Increases the number of MTN-55 able to be held to five. It also increases the sensing range of the T-UGS and MAV by 40%.
Spec Ops - Tier 3
Increases the time a player can steady a scope of a sniper rifle by 100%.
Sniper - Tier 1
Increases the amount of time an enemy is spotted by 45%.
Sniper - Tier 4
These give you quicker sprint speed, more available ammo magazines, one extra hand grenade, and allows you to fall from greater heights without taking any damage, respectively. This universal upgrade path is great for players who enjoy being at the front lines and leading the charge
These grant you increased protection from shots to the chest, a decreased rate of being suppressed, decreased damage from explosions, and a shorter time span before the out-of-combat health regeneration kicks in. If you are more defensive-minded, perhaps playing as Support from the sidelines, this can be an excellent choice.
Inspired by the fabled shadow warriors of the Orient, the “SHADOW” career grants you the mystical powers you need to infiltrate enemy territory without being seen. Okay, not really, but it grants you some perks that accumulated will give you an edge when going behind enemy lines.
MORE DEPLOYED EXPLOSIVES
AMMO BAG UPGRADE
The Shadow path was won in a contest by DICE that was meant to add the most popular of four paths created into Battlefield 4.
Some of the paths are based on Battlefield 2 classes, namely Anti-Tank, Spec Ops, and Sniper, based on the Anti-Tank, Special Forces, and Sniper classes respectively.