diff --git a/maps/includes/base.lua b/maps/includes/base.lua
index c73e3f9..b33f1ad 100644
--- a/maps/includes/base.lua
+++ b/maps/includes/base.lua
@@ -7,7 +7,9 @@
 -- Do not change this file.
 -----------------------------------------------------------------------------
 
+require "util.utils"
 Class = require "util.class"
+Collection = require "util.collection"
 
 -----------------------------------------------------------------------------
 -- defines
@@ -48,6 +50,47 @@ function baseclass:new (o)
 end
 
 
+-----------------------------------------------------------------------------
+-- set up pairs and ipairs for iterating the global entity list
+--
+-- Example usage:
+--
+--   for ent_id, ent in pairs(GlobalEntityList) do
+--     print(ent_id, ent)
+--   end
+--
+-- Note: The order of iteration is always arbitrary
+-----------------------------------------------------------------------------
+local GlobalEntityListIterator = function()
+	local entity = GlobalEntityList:FirstEntity()
+	return function()
+		local cur_ent = entity
+		entity = GlobalEntityList:NextEntity(cur_ent)
+		if cur_ent then
+			return cur_ent:GetId(), cur_ent
+		else
+			return nil
+		end
+	end
+end
+
+local ipairs_base = ipairs
+ipairs = function(t)
+	if t == GlobalEntityList then
+		return GlobalEntityListIterator()
+	end
+	return ipairs_base(t)
+end
+
+local pairs_base = pairs
+pairs = function(t)
+	if t == GlobalEntityList then
+		return GlobalEntityListIterator()
+	end
+	return pairs_base(t)
+end
+
+
 -----------------------------------------------------------------------------
 -- make luabind's class_info function safer
 -- (don't crash if class_info() is called on non-luabind objects)
diff --git a/maps/includes/util/collection.lua b/maps/includes/util/collection.lua
new file mode 100644
index 0000000..ea39e02
--- /dev/null
+++ b/maps/includes/util/collection.lua
@@ -0,0 +1,228 @@
+-- backwards compatibility for the Collection class
+
+local Class = require "util.class"
+require "util.utils"
+
+local function setup_items_key(self)
+	-- keep a usable reference to the base metatable
+	local real_obj = setmetatable({}, getmetatable(self))
+	-- add special handling of the items key
+	setmetatable(self, {
+		-- the items key returns an iterator
+		__index = function(t, k)
+			if k == "items" then
+				local i = 0
+				local n = self:Count()
+				return function()
+					i = i + 1
+					if i <= n then return self.entities[i] end
+				end
+			end
+			return real_obj[k]
+		end,
+		-- protect the items key from being assigned
+		__newindex = function(t, k, v)
+			if k == "items" then
+				return
+			end
+			real_obj[k] = v
+		end
+	})
+end
+
+local function get_param_as_table(param)
+	if param == nil then return {} end
+	if type(param) == "table" then return param end
+	return {param}
+end
+
+-- lua tables start at index 1
+local function to_lua_index(collection_index)
+	return collection_index+1
+end
+
+-- Collection started at index 0
+local function to_collection_index(lua_index)
+	return lua_index-1
+end
+
+local Collection = Class(function(self, entity_or_entities)
+	setup_items_key(self)
+	self.entities = get_param_as_table(entity_or_entities)
+end)
+
+Collection.filters = {
+	[CF.kNone] = function(entity) return true end,
+	[CF.kPlayers] = function(entity) return IsPlayer(entity) end,
+	[CF.kHumanPlayers] = function(entity) return IsPlayer(entity) and not CastToPlayer(entity):IsBot() end,
+	[CF.kBotPlayers] = function(entity) return IsPlayer(entity) and CastToPlayer(entity):IsBot() end,
+	[CF.kPlayerScout] = function(entity) return IsPlayer(entity) and CastToPlayer(entity):GetClass() == Player.kScout end,
+	[CF.kPlayerSniper] = function(entity) return IsPlayer(entity) and CastToPlayer(entity):GetClass() == Player.kSniper end,
+	[CF.kPlayerSoldier] = function(entity) return IsPlayer(entity) and CastToPlayer(entity):GetClass() == Player.kSoldier end,
+	[CF.kPlayerDemoman] = function(entity) return IsPlayer(entity) and CastToPlayer(entity):GetClass() == Player.kDemoman end,
+	[CF.kPlayerMedic] = function(entity) return IsPlayer(entity) and CastToPlayer(entity):GetClass() == Player.kMedic end,
+	[CF.kPlayerHWGuy] = function(entity) return IsPlayer(entity) and CastToPlayer(entity):GetClass() == Player.kHwguy end,
+	[CF.kPlayerPyro] = function(entity) return IsPlayer(entity) and CastToPlayer(entity):GetClass() == Player.kPyro end,
+	[CF.kPlayerSpy] = function(entity) return IsPlayer(entity) and CastToPlayer(entity):GetClass() == Player.kSpy end,
+	[CF.kPlayerEngineer] = function(entity) return IsPlayer(entity) and CastToPlayer(entity):GetClass() == Player.kEngineer end,
+	[CF.kPlayerCivilian] = function(entity) return IsPlayer(entity) and CastToPlayer(entity):GetClass() == Player.kCivilian end,
+	[CF.kPlayerScout] = function(entity) return IsPlayer(entity) and CastToPlayer(entity):GetClass() == Player.kScout end,
+	[CF.kTeams] = function(entity) return IsEntity(entity) and entity:GetTeamId() >= Team.kSpectator and entity:GetTeamId() <= Team.kGreen end,
+	[CF.kTeamSpec] = function(entity) return IsEntity(entity) and entity:GetTeamId() == Team.kSpectator end,
+	[CF.kTeamBlue] = function(entity) return IsEntity(entity) and entity:GetTeamId() == Team.kBlue end,
+	[CF.kTeamRed] = function(entity) return IsEntity(entity) and entity:GetTeamId() == Team.kRed end,
+	[CF.kTeamYellow] = function(entity) return IsEntity(entity) and entity:GetTeamId() == Team.kYellow end,
+	[CF.kTeamGreen] = function(entity) return IsEntity(entity) and entity:GetTeamId() == Team.kGreen end,
+	[CF.kProjectiles] = function(entity) return IsProjectile(entity) end,
+	[CF.kGrenades] = function(entity) return IsGrenade(entity) end,
+	[CF.kInfoScipts] = function(entity) return IsInfoScript(entity) end,
+	[CF.kInfoScript_Carried] = function(entity) return IsInfoScript(entity) and CastToInfoScript(entity):IsCarried() end,
+	[CF.kInfoScript_Dropped] = function(entity) return IsInfoScript(entity) and CastToInfoScript(entity):IsDropped() end,
+	[CF.kInfoScript_Returned] = function(entity) return IsInfoScript(entity) and CastToInfoScript(entity):IsReturned() end,
+	[CF.kInfoScript_Active] = function(entity) return IsInfoScript(entity) and CastToInfoScript(entity):IsActive() end,
+	[CF.kInfoScript_Inactive] = function(entity) return IsInfoScript(entity) and CastToInfoScript(entity):IsInactive() end,
+	[CF.kInfoScript_Removed] = function(entity) return IsInfoScript(entity) and CastToInfoScript(entity):IsRemoved() end,
+	[CF.kTraceBlockWalls] = function(entity) return true end, -- not applicable for this type of filtering
+	[CF.kBuildables] = function(entity) return IsBuildable(entity) end,
+	[CF.kDispenser] = function(entity) return IsDispenser(entity) end,
+	[CF.kSentrygun] = function(entity) return IsSentrygun(entity) end,
+	[CF.kDetpack] = function(entity) return IsDetpack(entity) end,
+	[CF.kJumpPad] = function(entity) return IsJumpPad(entity) end,
+}
+
+function Collection.PassesFilter(entity, filter)
+	if not filter then filter = CF.kNone end
+	assert(Collection.filters[filter], "Unknown filter: "..tostring(filter))
+	return Collection.filters[filter](entity)
+end
+
+function Collection.PassesFilters(entity, filters)
+	if not filters then return true end
+	filters = get_param_as_table(filters)
+	for _,filter in ipairs(filters) do
+		if not Collection.PassesFilter(entity, filter) then
+			return false
+		end
+	end
+	return true
+end
+
+function Collection:AddItem(entity_or_entities)
+	local entities_to_add = get_param_as_table(entity_or_entities)
+
+	for i,entity_to_add in ipairs(entities_to_add) do
+		table.insert(self.entities, entity_to_add)
+	end
+end
+
+function Collection:AddFiltered(entity_or_entities, filters)
+	local entities_to_add = get_param_as_table(entity_or_entities)
+
+	for i,entity_to_add in ipairs(entities_to_add) do
+		if Collection.PassesFilters(entity_to_add, filters) then
+			table.insert(self.entities, entity_to_add)
+		end
+	end
+end
+
+function Collection:RemoveItem(entity_or_entities)
+	local entities_to_find = get_param_as_table(entity_or_entities)
+
+	for i,entity_to_find in ipairs(entities_to_find) do
+		local i = self:FindItemIndex(entity_to_find)
+		if i then
+			table.remove(self.entities, to_lua_index(i))
+		end
+	end
+end
+
+function Collection:RemoveAllItems()
+	table.clear(self.entities)
+end
+
+function Collection:Count()
+	return #self.entities
+end
+
+function Collection:NumItems()
+	return self:Count()
+end
+
+function Collection:IsEmpty()
+	return self:Count() == 0
+end
+
+function Collection:HasItem(entity_or_entities)
+	local entities_to_find = get_param_as_table(entity_or_entities)
+
+	for i,entity_to_find in ipairs(entities_to_find) do
+		if self:FindItemIndex(entity_to_find) then
+			return true
+		end
+	end
+	return false
+end
+
+-- this is a strange function
+function Collection:GetItem(entity_or_entities)
+	local entities_to_find = get_param_as_table(entity_or_entities)
+
+	for i,entity_to_find in ipairs(entities_to_find) do
+		local i = self:FindItemIndex(entity_to_find)
+		if i then
+			return self:Element(i)
+		end
+	end
+end
+
+function Collection:FindItemIndex(entity_to_find)
+	for i,entity in ipairs(self.entities) do
+		if entity:GetId() == entity_to_find:GetId() then
+			return to_collection_index(i)
+		end
+	end
+	return nil
+end
+
+function Collection:Element(i)
+	return self.entities[to_lua_index(i)]
+end
+
+function Collection:GetByFilter(filters)
+	filters = get_param_as_table(filters)
+
+	-- optimization for players
+	local players_only = false
+	for _,filter in ipairs(filters) do
+		if filter >= CF.kPlayers and filter <= CF.kPlayerScout then
+			players_only = true
+			break
+		end
+	end
+
+	if players_only then
+		self:AddFiltered(GetPlayers(), filters)
+	else
+		for ent_id, entity in ipairs(GlobalEntityList) do
+			self:AddFiltered(entity, filters)
+		end
+	end
+end
+
+function Collection:GetByName(name_or_names, filters)
+	local names_to_find = get_param_as_table(name_or_names)
+	filters = get_param_as_table(filters)
+
+	for i,name_to_find in ipairs(names_to_find) do
+		self:AddFiltered(GetEntitiesByName(name_to_find), filters)
+	end
+end
+
+function Collection:GetInSphere(entity_or_origin, radius, filters)
+	filters = get_param_as_table(filters)
+	local origin = IsEntity(entity_or_origin) and entity_or_origin:GetOrigin() or entity_or_origin
+	local ignore_walls = not table.contains(filters, CF.kTraceBlockWalls)
+	self:AddFiltered(GetEntitiesInSphere(origin, radius, ignore_walls), filters)
+end
+
+return Collection
\ No newline at end of file
diff --git a/maps/includes/util/utils.lua b/maps/includes/util/utils.lua
new file mode 100644
index 0000000..d279d6c
--- /dev/null
+++ b/maps/includes/util/utils.lua
@@ -0,0 +1,28 @@
+
+function table.clear(tbl)
+	for k in pairs(tbl) do
+		tbl[k] = nil
+	end
+end
+
+function table.contains(tbl, element)
+	if tbl == nil then return false end
+	for _, value in pairs(tbl) do
+		if value == element then
+			return true
+		end
+	end
+	return false
+end
+
+function table.contains_any(tbl, elements)
+	if tbl == nil or elements == nil then return false end
+	for _, value in pairs(tbl) do
+		for _, element in pairs(elements) do
+			if value == element then
+				return true
+			end
+		end
+	end
+	return false
+end
\ No newline at end of file