the old system isnt needed really but sure i guess

code/__DEFINES/projectiles.dm

@@ -1,3 +1,12 @@
+/// This atom should be ricocheted off of from its inherent properties using standard % chance handling.
+#define PROJECTILE_RICOCHET_YES 1
+/// This atom should not be ricocheted off of from its inherent properties.
+#define PROJECTILE_RICOCHET_NO 2
+/// This atom should prevent any kind of projectile ricochet from its inherent properties.
+#define PROJECTILE_RICOCHET_PREVENT 3
+/// This atom should force a projectile ricochet from its inherent properties.
+#define PROJECTILE_RICOCHET_FORCE 4
+
 //bullet_act() return values
 #define BULLET_ACT_HIT				"HIT"		//It's a successful hit, whatever that means in the context of the thing it's hitting.
 #define BULLET_ACT_BLOCK			"BLOCK"		//It's a blocked hit, whatever that means in the context of the thing it's hitting.

code/game/atoms.dm

@@ -156,6 +156,13 @@
 
 	return ..()
 
+/**
+  * Checks if a projectile should ricochet off of us. Projectiles get final say.
+  * [__DEFINES/projectiles.dm] for return values.
+  */
+/atom/proc/check_projectile_ricochet(obj/item/projectile/P)
+	return (flags_1 & DEFAULT_RICOCHET_1)? PROJECTILE_RICOCHET_YES : PROJECTILE_RICOCHET_NO
+
 /atom/proc/handle_ricochet(obj/item/projectile/P)
 	var/turf/p_turf = get_turf(P)
 	var/face_direction = get_dir(src, p_turf)

code/game/objects/structures.dm

@@ -9,8 +9,10 @@
 	var/mob/living/structureclimber
 	var/broken = 0 //similar to machinery's stat BROKEN
 	layer = BELOW_OBJ_LAYER
-	flags_ricochet = RICOCHET_HARD
-	ricochet_chance_mod = 0.5
+	//ricochets on structures commented out for now because there's a lot of structures that /shouldnt/ be ricocheting and those need to be reviewed first
+	//flags_1 = DEFAULT_RICOCHET_1
+	//flags_ricochet = RICOCHET_HARD
+	//ricochet_chance_mod = 0.5
 
 /obj/structure/Initialize()
 	if (!armor)

code/game/objects/structures/window.dm

@@ -17,7 +17,6 @@ GLOBAL_LIST_EMPTY(electrochromatic_window_lookup)
 	layer = ABOVE_OBJ_LAYER //Just above doors
 	pressure_resistance = 4*ONE_ATMOSPHERE
 	anchored = TRUE //initially is 0 for tile smoothing
-	flags_1 = ON_BORDER_1
 	max_integrity = 25
 	var/ini_dir = null
 	var/state = WINDOW_OUT_OF_FRAME
@@ -38,7 +37,8 @@ GLOBAL_LIST_EMPTY(electrochromatic_window_lookup)
 	var/hitsound = 'sound/effects/Glasshit.ogg'
 	rad_insulation = RAD_VERY_LIGHT_INSULATION
 	rad_flags = RAD_PROTECT_CONTENTS
-	flags_ricochet = RICOCHET_HARD
+	flags_1 = ON_BORDER_1|DEFAULT_RICOCHET_1
+	flags_ricochet =  RICOCHET_HARD
 	ricochet_chance_mod = 0.4
 	attack_hand_speed = CLICK_CD_MELEE
 	attack_hand_is_action = TRUE

code/game/turfs/simulated/wall/mineral_walls.dm

@@ -191,7 +191,7 @@
 	icon = 'icons/turf/walls/shuttle_wall.dmi'
 	icon_state = "map-shuttle"
 	explosion_block = 3
-	flags_1 = CAN_BE_DIRTY_1
+	flags_1 = CAN_BE_DIRTY_1 | DEFAULT_RICOCHET_1
 	flags_ricochet = RICOCHET_SHINY | RICOCHET_HARD
 	sheet_type = /obj/item/stack/sheet/mineral/titanium
 	smooth = SMOOTH_MORE|SMOOTH_DIAGONAL

code/game/turfs/simulated/walls.dm

@@ -6,6 +6,7 @@
 	icon = 'icons/turf/walls/wall.dmi'
 	icon_state = "wall"
 	explosion_block = 1
+	flags_1 = DEFAULT_RICOCHET_1
 	flags_ricochet = RICOCHET_HARD
 	thermal_conductivity = WALL_HEAT_TRANSFER_COEFFICIENT
 	heat_capacity = 312500 //a little over 5 cm thick , 312500 for 1 m by 2.5 m by 0.25 m plasteel wall

code/modules/projectiles/projectile.dm

@@ -316,7 +316,7 @@
 	if(!trajectory)
 		return
 	var/turf/T = get_turf(A)
-	if(check_ricochet(A) && check_ricochet_flag(A)) //if you can ricochet, attempt to ricochet off the object
+	if(A.check_projectile_ricochet(src) && check_ricochet_flag(A) && check_ricochet(A)) //if you can ricochet, attempt to ricochet off the object
 		ricochets++
 		if(A.handle_ricochet(src))
 			on_ricochet(A) //if allowed, use autoaim to ricochet into someone, otherwise default to ricocheting off the object from above