diff --git a/gamedir/Data-1.13/Ja2_Options.INI b/gamedir/Data-1.13/Ja2_Options.INI
index 5fcba6924..82faf18e9 100644
--- a/gamedir/Data-1.13/Ja2_Options.INI
+++ b/gamedir/Data-1.13/Ja2_Options.INI
@@ -1207,6 +1207,33 @@ ASSASSIN_PROPABILITY_MODIFIER = 100
 
 BASE_SIGHT_RANGE = 13
 
+;------------------------------------------------------------------------------------------------------------------------------
+;Modifiers to the sight range in various light conditions. 0 = brightest, 15 = darkest
+;Important points: 
+;3: normal day
+;8: mid dawn
+;12: normal night time
+;values are in percent
+;Range: 1-100
+;------------------------------------------------------------------------------------------------------------------------------
+
+BRIGHTNESS_MOD_0 = 80
+BRIGHTNESS_MOD_1 = 86
+BRIGHTNESS_MOD_2 = 93
+BRIGHTNESS_MOD_3 = 100
+BRIGHTNESS_MOD_4 = 94
+BRIGHTNESS_MOD_5 = 88
+BRIGHTNESS_MOD_6 = 82
+BRIGHTNESS_MOD_7 = 76
+BRIGHTNESS_MOD_8 = 70
+BRIGHTNESS_MOD_9 = 64
+BRIGHTNESS_MOD_10 = 58
+BRIGHTNESS_MOD_11 = 51
+BRIGHTNESS_MOD_12 = 43
+BRIGHTNESS_MOD_13 = 30
+BRIGHTNESS_MOD_14 = 17
+BRIGHTNESS_MOD_15 = 9
+
 ;------------------------------------------------------------------------------------------------------------------------------
 ; Enable/disable tunnel vision: characters (friend and foe) cannot see behind, and have limited vision to the sides. 
 ; Some scopes and headgear may make vision even narrower.
diff --git a/gamedir/Data-1.13/TableData/Items/Items.xml b/gamedir/Data-1.13/TableData/Items/Items.xml
index cb3e51ef5..2687290f7 100644
--- a/gamedir/Data-1.13/TableData/Items/Items.xml
+++ b/gamedir/Data-1.13/TableData/Items/Items.xml
@@ -62,6 +62,7 @@
 		<HideMuzzleFlash>0</HideMuzzleFlash>
 		<Bipod>0</Bipod>
 		<RangeBonus>0</RangeBonus>
+		<PercentRangeBonus>0</PercentRangeBonus>
 		<ToHitBonus>0</ToHitBonus>
 		<BestLaserRange>0</BestLaserRange>
 		<AimBonus>0</AimBonus>
diff --git a/gamedir/Data-UB/Ja2_Options.ini b/gamedir/Data-UB/Ja2_Options.ini
index 0d566a8f6..4bbd5385b 100644
--- a/gamedir/Data-UB/Ja2_Options.ini
+++ b/gamedir/Data-UB/Ja2_Options.ini
@@ -1183,6 +1183,33 @@ ASSASSIN_PROPABILITY_MODIFIER = 100
 
 BASE_SIGHT_RANGE = 13
 
+;------------------------------------------------------------------------------------------------------------------------------
+;Modifiers to the sight range in various light conditions. 0 = brightest, 15 = darkest
+;Important points: 
+;3: normal day
+;8: mid dawn
+;12: normal night time
+;values are in percent
+;Range: 1-100
+;------------------------------------------------------------------------------------------------------------------------------
+
+BRIGHTNESS_MOD_0 = 80
+BRIGHTNESS_MOD_1 = 86
+BRIGHTNESS_MOD_2 = 93
+BRIGHTNESS_MOD_3 = 100
+BRIGHTNESS_MOD_4 = 94
+BRIGHTNESS_MOD_5 = 88
+BRIGHTNESS_MOD_6 = 82
+BRIGHTNESS_MOD_7 = 76
+BRIGHTNESS_MOD_8 = 70
+BRIGHTNESS_MOD_9 = 64
+BRIGHTNESS_MOD_10 = 58
+BRIGHTNESS_MOD_11 = 51
+BRIGHTNESS_MOD_12 = 43
+BRIGHTNESS_MOD_13 = 30
+BRIGHTNESS_MOD_14 = 17
+BRIGHTNESS_MOD_15 = 9
+
 ;------------------------------------------------------------------------------------------------------------------------------
 ; Enable/disable tunnel vision: characters (friend and foe) cannot see behind, and have limited vision to the sides. 
 ; Some scopes and headgear may make vision even narrower.
diff --git a/gamedir/Data/Ja2_Options.INI b/gamedir/Data/Ja2_Options.INI
index 3c9c5ebac..66f6a1201 100644
--- a/gamedir/Data/Ja2_Options.INI
+++ b/gamedir/Data/Ja2_Options.INI
@@ -1205,6 +1205,33 @@ ASSASSIN_PROPABILITY_MODIFIER = 100
 
 BASE_SIGHT_RANGE = 13
 
+;------------------------------------------------------------------------------------------------------------------------------
+;Modifiers to the sight range in various light conditions. 0 = brightest, 15 = darkest
+;Important points: 
+;3: normal day
+;8: mid dawn
+;12: normal night time
+;values are in percent
+;Range: 1-100
+;------------------------------------------------------------------------------------------------------------------------------
+
+BRIGHTNESS_MOD_0 = 80
+BRIGHTNESS_MOD_1 = 86
+BRIGHTNESS_MOD_2 = 93
+BRIGHTNESS_MOD_3 = 100
+BRIGHTNESS_MOD_4 = 94
+BRIGHTNESS_MOD_5 = 88
+BRIGHTNESS_MOD_6 = 82
+BRIGHTNESS_MOD_7 = 76
+BRIGHTNESS_MOD_8 = 70
+BRIGHTNESS_MOD_9 = 64
+BRIGHTNESS_MOD_10 = 58
+BRIGHTNESS_MOD_11 = 51
+BRIGHTNESS_MOD_12 = 43
+BRIGHTNESS_MOD_13 = 30
+BRIGHTNESS_MOD_14 = 17
+BRIGHTNESS_MOD_15 = 9
+
 ;------------------------------------------------------------------------------------------------------------------------------
 ; Enable/disable tunnel vision: characters (friend and foe) cannot see behind, and have limited vision to the sides. 
 ; Some scopes and headgear may make vision even narrower.