autoclimbable handrails on harm intent

code/game/objects/structures.dm

@@ -110,7 +110,7 @@
 
 /obj/structure/proc/do_climb(mob/living/user, mods)
 	if(!can_climb(user))
-		return
+		return FALSE
 
 	var/list/climbdata = list("climb_delay" = climb_delay)
 	SEND_SIGNAL(user, COMSIG_LIVING_CLIMB_STRUCTURE, climbdata)
@@ -120,10 +120,10 @@
 	user.visible_message(SPAN_WARNING("[user] starts [flags_atom & ON_BORDER ? "leaping over" : climb_over_string] \the [src]!"))
 
 	if(!do_after(user, final_climb_delay, INTERRUPT_NO_NEEDHAND, BUSY_ICON_GENERIC, numticks = 2))
-		return
+		return FALSE
 
 	if(!can_climb(user))
-		return
+		return FALSE
 
 	var/turf/TT = get_turf(src)
 	if(flags_atom & ON_BORDER)
@@ -145,6 +145,7 @@
 	user.forceMove(TT)
 	for(var/atom/movable/thing as anything in grabbed_things) // grabbed things aren't moved to the tile immediately to: make the animation better, preserve the grab
 		thing.forceMove(TT)
+	return TRUE
 
 /obj/structure/proc/structure_shaken()
 

code/game/objects/structures/barricade/handrail.dm

@@ -18,6 +18,18 @@
 	var/build_state = BARRICADE_BSTATE_SECURED
 	var/reinforced = FALSE //Reinforced to be a cade or not
 	var/can_be_reinforced = TRUE //can we even reinforce this handrail or not?
+	///Whether a ground z-level handrail allows auto-climbing on harm intent
+	var/autoclimb = TRUE
+
+/obj/structure/barricade/handrail/Initialize(mapload, ...)
+	. = ..()
+	if(!is_ground_level(z))
+		if(autoclimb && is_mainship_level(z))
+			RegisterSignal(SSdcs, COMSIG_GLOB_HIJACK_LANDED, PROC_REF(reset_autoclimb))
+		autoclimb = FALSE
+
+/obj/structure/barricade/handrail/proc/reset_autoclimb()
+	autoclimb = initial(autoclimb)
 
 /obj/structure/barricade/handrail/update_icon()
 	overlays.Cut()
@@ -40,6 +52,38 @@
 		if(E.icon_path && E.obj_icon_state_path)
 			overlays += image(E.icon_path, icon_state = E.obj_icon_state_path)
 
+/obj/structure/barricade/handrail/Collided(atom/movable/movable)
+	if(!ismob(movable))
+		return ..()
+
+	if(istype(movable, /mob/living/carbon/xenomorph/ravager) || istype(movable, /mob/living/carbon/xenomorph/crusher))
+		var/mob/living/carbon/xenomorph/xenomorph = movable
+		if(!xenomorph.stat)
+			visible_message(SPAN_DANGER("[xenomorph] plows straight through [src]!"))
+			deconstruct(FALSE)
+			return
+	else
+		if(!autoclimb)
+			return ..()
+
+		if(movable.last_bumped == world.time)
+			return ..()
+
+		var/mob/living/climber = movable
+		if(climber.a_intent != INTENT_HARM)
+			return ..()
+
+		climber.client?.move_delay += 3 DECISECONDS
+		if(do_climb(climber))
+			if(prob(25))
+				if(ishuman(climber))
+					var/mob/living/carbon/human/human = climber
+					human.apply_damage(5, BRUTE, no_limb_loss = TRUE)
+				else
+					climber.apply_damage(5, BRUTE)
+				climber.visible_message(SPAN_WARNING("[climber] injures themselves vaulting over [src]."), SPAN_WARNING("You hit yourself as you vault over [src]."))
+	..()
+
 /obj/structure/barricade/handrail/get_examine_text(mob/user)
 	. = ..()
 	switch(build_state)