Weapon modifications (DXHR)

In Deus Ex: Human Revolution, several different weapon modifications are available. Each one either improves one of the weapon's attributes or adds an extra feature to the weapon. Not all modifications are compatible with every weapon.

Weapon/modification combinations
Aside from "Ammo Rounds", "Special upgrade" and "#" then each column referers to a general upgrade. Numbers in these cells means base / max upgrade possible. Slash hyphen, "/ -", means no upgrade possible.

The last column, #, shows total number of upgrades the weapon can get.

Example: "2 / 5" means a base value of 2 with a maximum of 5, hence 3 upgrades can be added. Note: Laser modification is known to cause less accuracy (you need to aim higher than where the dot shows to hit) when in zoom/alt mode on both sniper rifles. May apply to other weapons too.

Ammo Capacity Upgrade
Description: Increases ammo capacity of given weapon, upgrade depends on weapon: Revolver and Sniper Rifle +1, Pistol +3, Shotgun +2, Combat Rifle and Machine Pistol +10, Heavy Rifle +25, Laser rifle +100.

Available locations:
 * Detroit, Sarif Headquarters, locked behind a level 5 security door, below the helipad.
 * Detroit, in the alley north-east of Sarif Headquarters, behind the level 3 electronically locked storage unit, where the player could possibly meet Ezekiel Sanders.
 * Detroit, underneath the floor (with a hole in it) in Derelict Row, in the area next to a sewer cover. This can easily be found during the Cloak & Daggers side quest.
 * Detroit, obtainable in Cloak & Daggers side quest, if you choose to give Jenny Alexander the crossbow and accept the option of arresting O'Malley. She will reward you with an Ammo Capacity Upgrade and 2000 credits.
 * Detroit, on the 4th level of a fire escape in Derelict Row, in front of the blue alley door. Reachable with the  jump enhancement aug.
 * Highland Park, FEMA camp, the warehouse with the elevator to the lower levels, in the small security building with a guard and openable window.
 * Hengsha, found in the east of the Youzhao district, on a rooftop behind two boxes and a grate. A long ladder leads up to the rooftop, nearby is a wall that can be punched out. A gated security door leads to this area which leads to Kuaigan District. This area is also close to the penthouse you're asked to check out in the main quest.
 * Hengsha, another one in the Youzhao district (to the west), in a secure storage room in an alley.
 * Hengsha, Tai Yong Medical, Lower City Factory, Maintenance Catwalk Room 2.
 * Montreal, Picus helipad, behind the fenced in area reachable through a breakable wall, hackable gate, or use of the jump enhancement.
 * Detroit (second visit), Chiron Building helipad, behind a breakable wall right after returning to Detroit.
 * Detroit (second visit), can be bought from Grayson.
 * Detroit (second visit), behind a breakable wall in the passageway after confronting Isaias Sandoval.
 * Hengsha, Harvester Hideout, in a level 5 safe in the living quarters area outside of Tong's office. You can find the code in a pocket secretary on one of the guard's or use an Automatic Unlocking Device, if needed.
 * Lower Hengsha, Belltower dock, purchasable from Lu Pin Rong in the sewers.
 * Singapore, immediately after you exit the transport pod from the cutscene transition to Omega Ranch, explore the area to find a storage room in the corner with an orange door. May need enhanced jump to get atop the scaffolding to drop down onto roof to enter from air vent, or hack (auto-hack) the level 5 security door.
 * Found at Panchaea, in the first building. Go up the stairs heading towards the elevator. From the stairs, facing the elevator, it is on the left about half way down the corridor on top of the very highest scaffolding, on top of a box with a sniper rifle.

Armor Piercing System
Description: Negates enemies' armor bonuses effectively doing more damage. Exclusive upgrade for the 10mm pistol.

Available locations:
 * Detroit, one can be found in Jensen's apartment in his secret stash behind the TV. Type the code, obtained from his personal computer, into the security panel on the wall near the kitchen to open it.
 * Detroit (second visit), purchasable from Grayson at the Orion gas station.
 * Hengsha, located in the Alice Garden Pods, under the south side stairs.
 * Hengsha (second visit), purchasable from Peng Xin Hao in the Youzhao district.

Burst Round System
Description: Fires two cartridges per shot, doubling the damage. Only for shotgun.

Available locations:
 * Detroit, purchasable from Grayson at the Orion gas station.
 * Detroit (second visit), locked behind a level 5 security door below the helipad of the Sarif building.
 * Lower Hengsha, Kuaigan District, at the very right side of the map (level 3). On a balcony just before the stairs going downwards.
 * Hengsha (second visit), purchasable from Peng Xin Hao in the Youzhao district.
 * Panchaea, from the starting area (while facing the entrance to the installation), the upgrade is hidden in one of the large metal containers on the left. It can be identified by one part of the door lying on the ground before it. Jump enhancement or a crate is required to reach it.

Cooling System
Description: Prevents rapid overheating of weapon during constant fire. Available for plasma and heavy rifles.

NOTE: In the PC version, the overheating bug for the plasma rifle has been fixed, making this upgrade necessary for it.

Available locations:


 * Picus Communications Sub-Basement, inside the armory.
 * Detroit (second visit), purchasable from Grayson at the Orion gas station.
 * Harvester Hideout (floor level -1), locked in a level 5 safe (inside a shipping container). It is on the same floor where a hackable stairway and elevator door are right next to each other.
 * Hengsha (second visit), purchasable from Lin Fu Ren in Hung Hua Hotel.
 * Belltower dock, purchasable from Lu Pin Rong, in the sewers.
 * Omega Ranch Hangar 18, in a secret room behind a box, near the doors that Sarif Industries scientists use to enter.
 * Panchaea, inside one of the rooms along with a Heavy rifle. The room has a broken door and large cart in front of it, and can only be accessed via ventshaft.

Damage Upgrade
Description: Increases weapon damage.

Available locations:
 * Detroit, Milwaukee Junction plant in Lab 2, storage room 3, inside a crate that a Purity First member is searching.
 * Detroit (during both visits), purchasable from Grayson at the Orion gas station.
 * Hengsha, purchasable from Lin Fu Ren in the Hung Hua Hotel.
 * Hengsha, Harvester Hideout, bottom level, in one of the cells in the back (2nd from the right when viewing head on) with a breakable wall.
 * Lower Hengsha, Belltower dock, in a locked room on the left sublevel of the outside area, guarded by a ceiling mounted turret at the far end (relative to the main warehouse), Room B.
 * Singapore, Omega Ranch, in the room where you can disable the signal jammer, behind a level 5 security door.

Explosive Rounds
Description: Allows the revolver to fire explosive rounds, increasing damage and adding splash.

Available locations:
 * Detroit (second visit), purchasable from Grayson at the Orion gas station.
 * Hengsha, purchasable from Peng Xin Hao in Alice Garden Pods.
 * Hengsha (second visit), purchasable from Peng Xin Hao in the Youzhao district.

Heat Targeting System
Description: Allows the rocket launcher missiles to home onto targets via heat-seeking.

Available locations:
 * Hengsha, Tai Yong Medical, in a level 5 safe behind Zhao's desk (passcode can be found from a pocket secretary in the previous room)
 * Detroit (second visit), purchasable from Seurat.
 * Hengsha (second visit), purchasable from Lin Fu Ren in the Hung Hua Hotel.

Laser Targeting System
Description: Replaces reticle with red-dot aiming. Available for 10mm Pistol, Revolver, Machine Pistol, Combat Rifle, Sniper Rifle, Plasma Rifle and Heavy Rifle.

Available locations:
 * Detroit, possible quest reward. Received from Tim Carella for completing the side quest, Lesser Evils.
 * Detroit, obtainable in a portable building outside the factory in Highland Park (near the electrical field).
 * Detroit (second visit), purchasable from Grayson at the Orion gas station.
 * Hengsha, purchasable from Lin Fu Ren in the Hung Hua Hotel.

Rate-of-Fire Upgrade
Description: The Rate Increment upgrade optimizes the trigger and firing mechanisms of most handguns, rifles, and combat firearms, thereby increasing their cyclic rate of fire.

Available locations:
 * Detroit Police Station armory, behind a locked door.
 * Detroit (second visit), purchasable from Seurat.
 * Hengsha, inside The Hive's interrogation room (accessible by air vent).
 * Hengsha, purchasable from Peng Xin Hao in the Alice Garden Pods.
 * Hengsha, hidden above Peng Xin Hao inside Alice Garden Pods (reachable by stacking boxes, breaking the weak wall in section 04, or through use of the jump enhancement).
 * Montreal, Picus TV, inside a men's room stall.
 * Lower Hangsha, Belltower dock, locked room on the left sublevel of the outside area, guarded by a ceiling mounted turret at the far end (relative to the main warehouse), Room A.

Reload Speed Upgrade
Description: The QuickFire Reload Kit improves the breech and feed mechanisms of most handguns, rifles, and combat firearms to decrease reloading time.

Available locations:
 * Detroit Police Station, inside the locker room near the morgue.
 * Detroit, Derelict Row, on the highest level of the fire escape in the entrance area. Can be obtained by object stacking, reaching for it after jumping or using the Jump Enhancement augmentation.
 * Highland Park, FEMA camp (floor level -4), in the security office near the elevator to level -5.
 * Hengsha, locked behind a level 2 secured garage, left of the Hung Hua Hotel's first floor.
 * Hengsha, Tai Yong Medical, just before taking the large freight elevator to Upper Hengsha, where you find the eBook "Better Than Nature?".
 * Picus Communications Sub-Basement, inside a locker in a locked office.
 * Detroit (second visit), purchasable from Grayson.
 * Lower Hengsha, Belltower dock, purchasable from Lu Pin Rong in the sewers.
 * Lower Hengsha, Belltower dock, level 4 of the warehouse interior, on a shelf (close to where the sniper is patrolling outside on the roof terrace). The level below (just over the railing) has an air vent which provides another entry point into the warehouse.
 * Singapore, Omega Ranch, inside the soldier barracks (same building where you can disable the signal jammer) near the break room. It's on the chair, inside a locked room with a Mahjong table. The code is 1385 (from a PDA on one of the first two patrolling guards you encounter in this mission), or hack (auto-hack) the level 4 security door.

Silencer
Description: Sound suppressor, reduces the noise made when firing a gun. Available for 10mm Pistol, Machine Pistol, and Combat rifle.

Available locations:
 * Detroit (first visit), purchasable from Seurat (located in the Detroit Downtown Apartments, 2nd floor).
 * Hengsha (both visits), purchasable from Lin Fu Ren in the Hung Hua Hotel.
 * Montreal - Picus Online News Division (Picus Newsroom 02, level 3), found in a drawer, in front of the turret.
 * Detroit (second visit), reward for completing the Smash the State side quest. Obtained by knocking out Jacob White instead of killing him.

Target-Leading System
Description: Anticipates a target's movement and shows where to shoot for a successful hit. For crossbows and tranquilizer rifles.

Available locations:
 * Highland Park, can be bought from MCB Gang Leader near the helipad.
 * Hengsha, one in a low-level locked garage west of The Hive.
 * Detroit (second visit), purchasable from Grayson at the gas station.
 * Detroit (second visit), purchasable from Seurat.
 * Hengsha (second visit), purchasable from Lin Fu Ren in the Hung Hua Hotel.
 * Lower Hengsha, Belltower dock, inside an open shipping container. May need enhanced jump to reach. From the main gate, just in front of the concrete barricades, look left above the Car Pro carports, on top of a stack of shipping containers.

Target-Seeking System
Description: Allows automatic headshots after locking on to a target by moving the reticule over the target. Only works when the reticule is not too far from the target. Available for the combat rifle and machine pistol. It also has the extremely helpful ability to allow a weapon to accurately target enemies from behind cover without exposing the user to enemy fire, even while blindfiring.

Available locations:
 * Hengsha (both visits), purchasable from Lin Fu Ren in the Hung Hua Hotel.
 * Detroit (second visit), purchasable from Seurat.
 * Hengsha (second visit), purchasable from Peng Xin Hao in the Youzhao district.
 * Lower Hangsha, Belltower dock, purchasable from Lu Pin Rong in the sewers.
 * Singapore, once you've uploaded the virus to the security terminal, you can enter the restricted area. Go inside the first door before the elevator and the upgrade is atop the lockers.

Detroit

 * 1) Inside the factory, first mission. Lab 2, storage 3 - Damage
 * 2) Inside the police station armory - Rate of Fire
 * 3) Locker near the police morgue - Reload Speed
 * 4) Helipad storage at Sarif HQ - Ammo capacity
 * 5) Alley east and near Sarif HQ - Ammo capacity
 * 6) Underneath the floor in a hole in Derelict Row, in the area next to a sewer cover. This can easily be found during Cloak & Daggers sidequest. - Ammo Capacity
 * 7) Possible reward for Cloak & Daggers sidequest when crossbow is given up - Ammo Capacity
 * 8) Quest reward for completing the Lesser Evils quest - Laser sight
 * 9) Gang Leader near Highland park - Target Leading system
 * 10) FEMA camp, ground level, first little trailer outside the main building - Laser sight
 * 11) FEMA camp, Level -4, in the security office near the elevator to Level -5 - Reload Speed
 * 12) FEMA camp, the warehouse with the elevator to the lower levels, in the small security building with a guard and openable window - Ammo capacity
 * 13) First visit to Seurat - Silencer
 * 14) First visit to Grayson - Burst Round System, Damage upgrade
 * 15) Second visit to Seurat - Rate of Fire, Target Leading system, Target Seeking System, Heat Seeking system
 * 16) Second visit to Grayson - Explosive Rounds, Cooling system, Armor Piercing system, Target leading system, Laser sight, Ammo Capacity, Damage Upgrade, Reload Speed
 * 17) Quest reward from Smash the State sidequest during the second visit to Detroit. Obtained by knocking out Jacob White instead of killing him. - Silencer
 * 18) Just after confronting Sandoval, there is a breakable wall to your right - Ammo Capacity

Hengsha

 * 1) One locked behind a level 2 secured garage left of the Hung Hua Hotel's first floor. - Reload Speed
 * 2) One in a low-level locked garage west of The Hive. - Target Leading
 * 3) One inside The Hive's interrogation room (accessible by air vent). - Rate-of-Fire
 * 4) At the east of the highest level (3) of Kuaigan District, an upgrade can be found on a balcony (on the west side of the street), just before the stairs going to the lower level (2). - Burst Round System
 * 5) Hidden above Peng Xin Hao inside Alice Garden Pods (reachable by stacking boxes, breaking the weak wall in section 04, or through use of the jump enhancement). - Rate-of-Fire
 * 6) Located in the Alice Garden Pods under the south side stairs. - Armor Piercing
 * 7) Found in the east of Youzhao district, on a rooftop behind two boxes and a grate. A long ladder leads up to the roofop, nearby is a wall that can be punched out. A gated security door leads to this area which leads to Kuaigan District. This area is also close to the penthouse you're asked to check out in the main quest. - Ammo
 * 8) Another one also in Youzhao district west, in a secure storage room in an alley. - Ammo
 * 9) First visit to Lin Fu Ren in Hung Hua Hotel - Damage, Laser, Silencer, Target Seeking
 * 10) First visit to Peng Xin Hao in Alice Garden Pods - Rate-of-Fire, Explosive Rounds
 * 11) Found in Tai Yong Medical Lower City Factory, Maintenance Catwalk Room 2. - Ammo
 * 12) Where you find the eBook Better Than Nature in the Pangu to Tai Yong Medical. - Reload Speed
 * 13) Tai Yong Medical Penthouse, in a safe behind Zhao's desk (Hacking 5 required, or passcode from pocket secretary in room prior) - Heat Targeting
 * 14) Harvester Hideout, level -1, in a Level 5 safe in the NW lab - Cooling System
 * 15) Harvester Hideout, bottom level, in one of the cells with a breakable wall. - Damage
 * 16) In the Harvester Hideout, in a Level 5 safe in the living quarters area outside of Tong's office. You can find the code in a pocket secretary on one of the guard's or use an autohack device, if needed - Ammo
 * 17) Second visit to Lin Fu Ren in Hung Hua Hotel - Laser, Silencer, Target Leading, Target Seeking, Cooling System, Heat Targeting
 * 18) Second visit to Peng Xin Hao in Youzhao District - Armour Piercing, Target Seeking, Burst round, Explosive rounds
 * 19) Visit to Lu Pin Rong underneath Belltower dock - Reload Speed, Ammo, Target Seeking, Cooling System
 * 20) Belltower dock, locked room on the left sublevel of the outside area, guarded by a ceiling mounted turret at the far end (relative to the main warehouse), Room A. - Rate-of-Fire
 * 21) Belltower dock, locked room on the left sublevel of the outside area, guarded by a ceiling mounted turret at the far end (relative to the main warehouse), Room B. - Damage
 * 22) Belltower dock, inside an open shipping container. May need enhanced jump to reach. From the main gate, just in front of the concrete barricades, look left above the Car Pro carports, on top of a stack of shipping containers. - Target Leading
 * 23) Belltower dock, level 4 (where sniper is patrolling outside on roof terrace) of warehouse, interior on a shelf. The level below (just over the railing) has an air vent which provides another entry point into the warehouse proper. - Reload Speed

Montreal

 * 1) In a fenced in area near the helipad on the roof - Ammo Capacity
 * 2) Inside men's restroom on level 6 of Picus TV, immediatelly before the elevator room - Rate-of-Fire
 * 3) Found in a drawer behind some boxes in level 3 broadcast room, in front of the turret - Silencer
 * 4) In the armory of the Picus Sub-Basement - Cooling System
 * 5) Inside a locker within a locked office of the Picus Sub-Basement - Reload Speed

Singapore

 * 1) Immediately after you exit the transport pod from the cutscene, explore the area to find a storage room in the corner with an orange door. May need enhanced jump to get atop the scaffolding to drop down onto roof to enter from air vent, or hack the level 5 door. - Ammo
 * 2) Omega Ranch, in the room where you disable the signal jammer, behind a level 5 security door. - Damage
 * 3) In Singapore's Omega Ranch, inside the soldier barracks (same building where you disable the signal jammer) near the break room, sitting on a chair inside a locked room with a mahjong table. The code is 1385 (that you picked up from a PDA from the first two patrolling guards you encounter in this mission), or (auto)hack the level 4 security door. - Reload Speed