diff --git a/data/ai/lua/ai_helper.lua b/data/ai/lua/ai_helper.lua
index 14b79abb0bad..624da59cf2b0 100644
--- a/data/ai/lua/ai_helper.lua
+++ b/data/ai/lua/ai_helper.lua
@@ -678,7 +678,7 @@ function ai_helper.get_closest_location(hex, location_filter, unit)
 
         if unit then
             for _,loc in ipairs(locs) do
-                local movecost = wesnoth.unit_movement_cost(unit, wesnoth.get_terrain(loc[1], loc[2]))
+                local movecost = unit:movement(wesnoth.get_terrain(loc[1], loc[2]))
                 if (movecost <= unit.max_moves) then return loc end
             end
         else
@@ -709,7 +709,7 @@ function ai_helper.get_passable_locations(location_filter, unit)
     if unit then
         local locs = {}
         for _,loc in ipairs(all_locs) do
-            local movecost = wesnoth.unit_movement_cost(unit, wesnoth.get_terrain(loc[1], loc[2]))
+            local movecost = unit:movement(wesnoth.get_terrain(loc[1], loc[2]))
             if (movecost <= unit.max_moves) then table.insert(locs, loc) end
         end
         return locs
@@ -1364,7 +1364,7 @@ function ai_helper.find_path_with_shroud(unit, x, y, cfg)
                 if (u.side ~= viewing_side)
                     and (not ai_helper.is_visible_unit(viewing_side, u))
                 then
-                    wesnoth.extract_unit(u)
+                    u:extract()
                     table.insert(extracted_units, u)
                 end
             end
@@ -1376,7 +1376,7 @@ function ai_helper.find_path_with_shroud(unit, x, y, cfg)
         path, cost = wesnoth.find_path(unit, x, y, cfg_copy)
 
         for _,extracted_unit in ipairs(extracted_units) do
-            wesnoth.put_unit(extracted_unit)
+            extracted_unit:to_map()
         end
     else
         path, cost = wesnoth.find_path(unit, x, y, cfg)
@@ -1665,7 +1665,7 @@ function ai_helper.get_attacks(units, cfg)
                     for _,target in ipairs(attack_hex_map:get(loc[1], loc[2])) do
                         local att_stats, def_stats
                         if cfg.simulate_combat then
-                            local unit_dst = wesnoth.copy_unit(unit)
+                            local unit_dst = unit:clone()
                             unit_dst.x, unit_dst.y = loc[1], loc[2]
 
                             local enemy = all_units[target.i]
diff --git a/data/ai/lua/battle_calcs.lua b/data/ai/lua/battle_calcs.lua
index 13def8eae435..931d13f02250 100644
--- a/data/ai/lua/battle_calcs.lua
+++ b/data/ai/lua/battle_calcs.lua
@@ -76,7 +76,7 @@ function battle_calcs.unit_attack_info(unit, cache)
 
     local attack_types = { "arcane", "blade", "cold", "fire", "impact", "pierce" }
     for _,attack_type in ipairs(attack_types) do
-        unit_info.resist_mod[attack_type] = wesnoth.unit_resistance(unit, attack_type) / 100.
+        unit_info.resist_mod[attack_type] = unit:resistance(attack_type) / 100.
     end
 
     if cache then cache[cind] = unit_info end
@@ -680,8 +680,8 @@ function battle_calcs.battle_outcome(attacker, defender, cfg, cache)
     if (def_max_hits > att_strikes) then def_max_hits = att_strikes end
 
     -- Probability of landing a hit
-    local att_hit_prob = wesnoth.unit_defense(defender, wesnoth.get_terrain(defender.x, defender.y)) / 100.
-    local def_hit_prob = wesnoth.unit_defense(attacker, wesnoth.get_terrain(dst[1], dst[2])) / 100.
+    local att_hit_prob = defender:defense(wesnoth.get_terrain(defender.x, defender.y)) / 100.
+    local def_hit_prob = attacker:defense(wesnoth.get_terrain(dst[1], dst[2])) / 100.
 
     -- Magical: attack and defense, and under all circumstances
     if att_attack.magical then att_hit_prob = 0.7 end
@@ -731,7 +731,7 @@ function battle_calcs.simulate_combat_loc(attacker, dst, defender, weapon)
     -- when on terrain of same type as that at @dst, which is of form { x, y }
     -- If @weapon is set, use that weapon (Lua index starting at 1), otherwise use best weapon
 
-    local attacker_dst = wesnoth.copy_unit(attacker)
+    local attacker_dst = attacker:clone()
     attacker_dst.x, attacker_dst.y = dst[1], dst[2]
 
     if weapon then
@@ -932,7 +932,7 @@ function battle_calcs.attack_rating(attacker, defender, dst, cfg, cache)
     -- We don't need a bonus for good terrain for the attacker, as that is covered in the damage calculation
     -- However, we add a small bonus for good terrain defense of the _defender_ on the _attack_ hex
     -- This is in order to take good terrain away from defender on next move, all else being equal
-    local defender_defense = - wesnoth.unit_defense(defender, wesnoth.get_terrain(dst[1], dst[2])) / 100.
+    local defender_defense = - defender:defense(wesnoth.get_terrain(dst[1], dst[2])) / 100.
     defender_value = defender_value + defender_defense * defense_weight
 
     -- Get a very small bonus for hexes in between defender and AI leader
@@ -1173,7 +1173,7 @@ function battle_calcs.get_attack_map_unit(unit, cfg)
         for _,unit in ipairs(all_units) do
             if (unit.moves > 0) then
                 table.insert(units_MP, unit)
-                wesnoth.extract_unit(unit)
+                unit:extract()
             end
         end
     end
@@ -1183,7 +1183,7 @@ function battle_calcs.get_attack_map_unit(unit, cfg)
 
     -- Put the units back out there
     if (unit.side ~= wesnoth.current.side) then
-        for _,uMP in ipairs(units_MP) do wesnoth.put_unit(uMP) end
+        for _,uMP in ipairs(units_MP) do uMP:to_map() end
     end
 
     for _,loc in ipairs(initial_reach) do
@@ -1312,7 +1312,7 @@ function battle_calcs.best_defense_map(units, cfg)
     local defense_map = LS.create()
 
     if cfg.ignore_these_units then
-        for _,unit in ipairs(cfg.ignore_these_units) do wesnoth.extract_unit(unit) end
+        for _,unit in ipairs(cfg.ignore_these_units) do unit:extract() end
     end
 
     for _,unit in ipairs(units) do
@@ -1326,7 +1326,7 @@ function battle_calcs.best_defense_map(units, cfg)
         if max_moves then unit.moves = old_moves end
 
         for _,loc in ipairs(reach) do
-            local defense = 100 - wesnoth.unit_defense(unit, wesnoth.get_terrain(loc[1], loc[2]))
+            local defense = 100 - unit:defense(wesnoth.get_terrain(loc[1], loc[2]))
 
             if (defense > (defense_map:get(loc[1], loc[2]) or -9e99)) then
                 defense_map:insert(loc[1], loc[2], defense)
@@ -1335,7 +1335,7 @@ function battle_calcs.best_defense_map(units, cfg)
     end
 
     if cfg.ignore_these_units then
-        for _,unit in ipairs(cfg.ignore_these_units) do wesnoth.put_unit(unit) end
+        for _,unit in ipairs(cfg.ignore_these_units) do unit:to_map() end
     end
 
     return defense_map
@@ -1534,7 +1534,7 @@ function battle_calcs.get_attack_combos_subset(units, enemy, cfg)
                     -- Store information about it in 'loc' and add this to 'locs'
                     -- Want coordinates (dst) and terrain defense (for sorting)
                     loc.dst = xa * 1000 + ya
-                    loc.hit_prob = wesnoth.unit_defense(unit, wesnoth.get_terrain(xa, ya))
+                    loc.hit_prob = unit:defense(wesnoth.get_terrain(xa, ya))
                     table.insert(locs, loc)
 
                     -- Also mark this hex as usable
diff --git a/data/ai/lua/ca_high_xp_attack.lua b/data/ai/lua/ca_high_xp_attack.lua
index ec1536bd874e..7d0403329e6c 100644
--- a/data/ai/lua/ca_high_xp_attack.lua
+++ b/data/ai/lua/ca_high_xp_attack.lua
@@ -82,7 +82,7 @@ function ca_attack_highxp:evaluation(cfg, data)
     if (not target_infos[1]) then return 0 end
 
     -- The following location sets are used so that we at most need to call
-    -- find_reach() and wesnoth.copy_unit() once per unit
+    -- find_reach() and unit:clone() once per unit
     local reaches = LS.create()
     local attacker_copies = LS.create()
 
@@ -217,7 +217,7 @@ function ca_attack_highxp:evaluation(cfg, data)
                 if attacker_copies:get(attacker.x, attacker.y) then
                     attacker_copy = attacker_copies:get(attacker.x, attacker.y)
                 else
-                    attacker_copy = wesnoth.copy_unit(attacker)
+                    attacker_copy = attacker:clone()
                     attacker_copies:insert(attacker.x, attacker.y, attacker_copy)
                 end
 
diff --git a/data/ai/lua/generic_recruit_engine.lua b/data/ai/lua/generic_recruit_engine.lua
index 3cab9e9987f0..2e15ad7232d0 100644
--- a/data/ai/lua/generic_recruit_engine.lua
+++ b/data/ai/lua/generic_recruit_engine.lua
@@ -91,7 +91,7 @@ return {
             local best_defense = 100
 
             for i, terrain in ipairs(terrain_archetypes) do
-                local defense = wesnoth.unit_defense(unit, terrain)
+                local defense = unit:defense(terrain)
                 if defense < best_defense then
                     best_defense = defense
                 end
@@ -199,7 +199,7 @@ return {
                                 if wml.get_child(special, 'drains') and drainable(attacker) then
                                     -- TODO: calculate chance to hit
                                     -- currently assumes 50% chance to hit using supplied constant
-                                    local attacker_resistance = wesnoth.unit_resistance(attacker, defender_attack.type)
+                                    local attacker_resistance = attacker:resistance(defender_attack.type)
                                     drain_recovery = (defender_attack.damage*defender_attack.number*attacker_resistance*attacker_defense/2)/10000
                                 end
                             end
@@ -207,7 +207,7 @@ return {
                     end
 
                     defense = defense/100.0
-                    local resistance = wesnoth.unit_resistance(defender, attack.type)
+                    local resistance = defender:resistance(attack.type)
                     if steadfast and (resistance < 100) then
                         resistance = 100 - ((100 - resistance) * 2)
                         if (resistance < 50) then
@@ -260,8 +260,8 @@ return {
                 name = "X",
                 random_gender = false
             }
-            local can_poison = poisonable(unit) and (not wesnoth.unit_ability(unit, 'regenerate'))
-            local flat_defense = wesnoth.unit_defense(unit, "Gt")
+            local can_poison = poisonable(unit) and (not unit:ability('regenerate'))
+            local flat_defense = unit:defense("Gt")
             local best_defense = get_best_defense(unit)
 
             local recruit = wesnoth.create_unit {
@@ -270,10 +270,10 @@ return {
                 name = "X",
                 random_gender = false
             }
-            local recruit_flat_defense = wesnoth.unit_defense(recruit, "Gt")
+            local recruit_flat_defense = recruit:defense("Gt")
             local recruit_best_defense = get_best_defense(recruit)
 
-            local can_poison_retaliation = poisonable(recruit) and (not wesnoth.unit_ability(recruit, 'regenerate'))
+            local can_poison_retaliation = poisonable(recruit) and (not recruit:ability('regenerate'))
             best_flat_attack, best_flat_damage, flat_poison = get_best_attack(recruit, unit, flat_defense, recruit_best_defense, can_poison)
             best_high_defense_attack, best_high_defense_damage, high_defense_poison = get_best_attack(recruit, unit, best_defense, recruit_flat_defense, can_poison)
             best_retaliation, best_retaliation_damage, retaliation_poison = get_best_attack(unit, recruit, recruit_flat_defense, best_defense, can_poison_retaliation)
@@ -767,10 +767,10 @@ return {
                 if can_slow(recruit_unit) then
                     unit_score["slows"] = true
                 end
-                if wesnoth.match_unit(recruit_unit, { ability = "healing" }) then
+                if recruit_unit:matches { ability = "healing" } then
                     unit_score["heals"] = true
                 end
-                if wesnoth.match_unit(recruit_unit, { ability = "skirmisher" }) then
+                if recruit_unit:matches { ability = "skirmisher" } then
                     unit_score["skirmisher"] = true
                 end
                 recruitable_units[recruit_id] = recruit_unit
diff --git a/data/ai/lua/generic_rush_engine.lua b/data/ai/lua/generic_rush_engine.lua
index d6ab5c2ecb55..51c9b2d21020 100644
--- a/data/ai/lua/generic_rush_engine.lua
+++ b/data/ai/lua/generic_rush_engine.lua
@@ -199,7 +199,7 @@ return {
                     for i,loc in ipairs(close_villages) do
                         local path_village, cost_village = wesnoth.find_path(leader, loc[1], loc[2])
                         if cost_village <= leader.moves then
-                            local dummy_leader = wesnoth.copy_unit(leader)
+                            local dummy_leader = leader:clone()
                             dummy_leader.x = loc[1]
                             dummy_leader.y = loc[2]
                             local path_keep, cost_keep = wesnoth.find_path(dummy_leader, best_loc[1], best_loc[2])
@@ -454,14 +454,14 @@ return {
                     if defender.canrecruit then rating = rating + 1000 end
 
                     -- Enemies that can regenerate are not good targets
-                    if wesnoth.unit_ability(defender, 'regenerate') then rating = rating - 1000 end
+                    if defender:ability('regenerate') then rating = rating - 1000 end
 
                     -- More priority to enemies on strong terrain
-                    local defender_defense = 100 - wesnoth.unit_defense(defender, wesnoth.get_terrain(defender.x, defender.y))
+                    local defender_defense = 100 - defender:defense(wesnoth.get_terrain(defender.x, defender.y))
                     rating = rating + defender_defense / 4.
 
                     -- For the same attacker/defender pair, go to strongest terrain
-                    local attack_defense = 100 - wesnoth.unit_defense(attacker, wesnoth.get_terrain(a.dst.x, a.dst.y))
+                    local attack_defense = 100 - attacker:defense(wesnoth.get_terrain(a.dst.x, a.dst.y))
                     rating = rating + attack_defense / 2.
                     --print('rating', rating)
 
diff --git a/data/ai/lua/retreat.lua b/data/ai/lua/retreat.lua
index ea6c047fd033..19bc93a4ee88 100644
--- a/data/ai/lua/retreat.lua
+++ b/data/ai/lua/retreat.lua
@@ -12,7 +12,7 @@ local retreat_functions = {}
 function retreat_functions.min_hp(unit)
     -- The minimum hp to retreat is a function of level and terrain defense
     -- We want to stay longer on good terrain and leave early on very bad terrain
-    local hp_per_level = wesnoth.unit_defense(unit, wesnoth.get_terrain(unit.x, unit.y))/15
+    local hp_per_level = unit:defense(wesnoth.get_terrain(unit.x, unit.y))/15
     local level = unit.level
 
     -- Leaders are considered to be higher level because of their value
@@ -38,7 +38,7 @@ function retreat_functions.retreat_injured_units(units)
     local regen, non_regen = {}, {}
     for i,u in ipairs(units) do
         if u.hitpoints < retreat_functions.min_hp(u) then
-            if wesnoth.unit_ability(u, 'regenerate') then
+            if u:ability('regenerate') then
                 table.insert(regen, u)
             else
                 table.insert(non_regen, u)
@@ -176,7 +176,7 @@ function retreat_functions.get_retreat_injured_units(healees, regenerates)
                 rating = rating - enemy_count * 100000
 
                 -- Penalty based on terrain defense for unit
-                rating = rating - wesnoth.unit_defense(u, wesnoth.get_terrain(loc[1], loc[2]))/10
+                rating = rating - u:defense(wesnoth.get_terrain(loc[1], loc[2]))/10
 
                 if (loc[1] == u.x) and (loc[2] == u.y) and (not u.status.poisoned) then
                     if enemy_count == 0 then
diff --git a/data/ai/micro_ais/cas/ca_assassin_move.lua b/data/ai/micro_ais/cas/ca_assassin_move.lua
index e81fe6681eeb..9414299607d1 100644
--- a/data/ai/micro_ais/cas/ca_assassin_move.lua
+++ b/data/ai/micro_ais/cas/ca_assassin_move.lua
@@ -25,7 +25,7 @@ local function custom_cost(x, y, unit, enemy_rating_map, prefer_map)
     --    must return values >=1 for the a* search to work.
 
     local terrain = wesnoth.get_terrain(x, y)
-    local move_cost = wesnoth.unit_movement_cost(unit, terrain)
+    local move_cost = unit:movement(terrain)
 
     move_cost = move_cost + (enemy_rating_map:get(x, y) or 0)
 
@@ -66,7 +66,7 @@ function ca_assassin_move:execution(cfg)
         if (not enemy.status.petrified) then
             -- Need to "move" enemy next to unit for attack calculation
             -- Do this with a unit copy, so that no actual unit has to be moved
-            local enemy_copy = wesnoth.copy_unit(enemy)
+            local enemy_copy = enemy:clone()
 
             -- First get the reach of the enemy with full moves though
             enemy_copy.moves = enemy_copy.max_moves
@@ -95,7 +95,7 @@ function ca_assassin_move:execution(cfg)
     -- Penalties for damage by enemies
     local enemy_rating_map = LS.create()
     enemy_damage_map:iter(function(x, y, enemy_damage)
-        local hit_chance = (wesnoth.unit_defense(unit, wesnoth.get_terrain(x, y))) / 100.
+        local hit_chance = (unit:defense(wesnoth.get_terrain(x, y))) / 100.
 
         local rating = hit_chance * enemy_damage
         rating = rating / unit.max_hitpoints
@@ -105,7 +105,7 @@ function ca_assassin_move:execution(cfg)
     end)
 
     -- Penalties for blocked hexes and ZOC
-    local is_skirmisher = wesnoth.unit_ability(unit, "skirmisher")
+    local is_skirmisher = unit:ability("skirmisher")
     for _,enemy in ipairs(enemies) do
         -- Hexes an enemy is on get a very large penalty
         enemy_rating_map:insert(enemy.x, enemy.y, (enemy_rating_map:get(enemy.x, enemy.y) or 0) + 100)
diff --git a/data/ai/micro_ais/cas/ca_bottleneck_move.lua b/data/ai/micro_ais/cas/ca_bottleneck_move.lua
index ff9868e3f98b..ed6822d5c4e3 100644
--- a/data/ai/micro_ais/cas/ca_bottleneck_move.lua
+++ b/data/ai/micro_ais/cas/ca_bottleneck_move.lua
@@ -14,7 +14,7 @@ local function bottleneck_is_my_territory(map, enemy_map)
     -- If there is no leader, use first unit found
     local unit = wesnoth.get_units { side = wesnoth.current.side, canrecruit = 'yes' }[1]
     if (not unit) then unit = wesnoth.get_units { side = wesnoth.current.side }[1] end
-    local dummy_unit = wesnoth.copy_unit(unit)
+    local dummy_unit = unit:clone()
 
     local territory_map = LS.create()
     local width, height = wesnoth.get_map_size()
diff --git a/data/ai/micro_ais/cas/ca_fast_attack_utils.lua b/data/ai/micro_ais/cas/ca_fast_attack_utils.lua
index df1fa9911553..f257cd808412 100644
--- a/data/ai/micro_ais/cas/ca_fast_attack_utils.lua
+++ b/data/ai/micro_ais/cas/ca_fast_attack_utils.lua
@@ -164,7 +164,7 @@ function ca_fast_attack_utils.single_unit_info(unit_proxy)
     local attack_types = { "arcane", "blade", "cold", "fire", "impact", "pierce" }
     single_unit_info.resistances = {}
     for _,attack_type in ipairs(attack_types) do
-        single_unit_info.resistances[attack_type] = wesnoth.unit_resistance(unit_proxy, attack_type) / 100.
+        single_unit_info.resistances[attack_type] = unit_proxy:resistance(attack_type) / 100.
     end
 
     return single_unit_info
@@ -187,7 +187,7 @@ function ca_fast_attack_utils.get_unit_copy(id, gamedata)
 
     if (not gamedata.unit_copies[id]) then
         local unit_proxy = wesnoth.get_units { id = id }[1]
-        gamedata.unit_copies[id] = wesnoth.copy_unit(unit_proxy)
+        gamedata.unit_copies[id] = unit_proxy:clone()
     end
 
     return gamedata.unit_copies[id]
@@ -209,7 +209,7 @@ function ca_fast_attack_utils.get_unit_defense(unit_copy, x, y, defense_maps)
     if (not defense_maps[unit_copy.id][x]) then defense_maps[unit_copy.id][x] = {} end
 
     if (not defense_maps[unit_copy.id][x][y]) then
-        local defense = (100. - wesnoth.unit_defense(unit_copy, wesnoth.get_terrain(x, y))) / 100.
+        local defense = (100. - unit_copy:defense(wesnoth.get_terrain(x, y))) / 100.
         defense_maps[unit_copy.id][x][y] = { defense = defense }
     end
 
diff --git a/data/ai/micro_ais/cas/ca_fast_move.lua b/data/ai/micro_ais/cas/ca_fast_move.lua
index f4166f53a571..973636711d3f 100644
--- a/data/ai/micro_ais/cas/ca_fast_move.lua
+++ b/data/ai/micro_ais/cas/ca_fast_move.lua
@@ -243,7 +243,7 @@ function ca_fast_move:execution(cfg)
             if cfg.dungeon_mode then
                 table.sort(pre_ratings, function(a,b) return (a.rating > b.rating) end)
 
-                wesnoth.extract_unit(unit)
+                unit:extract()
                 local old_x, old_y = unit.x, unit.y
 
                 local max_rating = -9e99
@@ -264,7 +264,7 @@ function ca_fast_move:execution(cfg)
                 end
 
                 unit.x, unit.y = old_x, old_y
-                wesnoth.put_unit(unit)
+                unit:to_map()
             end
 
             if best_hex then
diff --git a/data/ai/micro_ais/cas/ca_goto.lua b/data/ai/micro_ais/cas/ca_goto.lua
index 95e2442e3be4..d6071b8a0e40 100644
--- a/data/ai/micro_ais/cas/ca_goto.lua
+++ b/data/ai/micro_ais/cas/ca_goto.lua
@@ -8,7 +8,7 @@ local M = wesnoth.map
 
 local function custom_cost(x, y, unit, enemy_map, enemy_attack_map, multiplier)
     local terrain = wesnoth.get_terrain(x, y)
-    local move_cost = wesnoth.unit_movement_cost(unit, terrain)
+    local move_cost = unit:movement(terrain)
 
     move_cost = move_cost + (enemy_map:get(x,y) or 0)
     move_cost = move_cost + (enemy_attack_map.units:get(x,y) or 0) * multiplier
@@ -149,14 +149,14 @@ function ca_goto:execution(cfg, data)
                     if cfg.ignore_enemy_at_goal then
                         enemy_at_goal = wesnoth.get_unit(loc[1], loc[2])
                         if enemy_at_goal and wesnoth.is_enemy(wesnoth.current.side, enemy_at_goal.side) then
-                             wesnoth.extract_unit(enemy_at_goal)
+                             enemy_at_goal:extract()
                         else
                             enemy_at_goal = nil
                         end
                     end
                     path, cost = AH.find_path_with_shroud(unit, loc[1], loc[2], { ignore_units = cfg.ignore_units })
                     if enemy_at_goal then
-                        wesnoth.put_unit(enemy_at_goal)
+                        enemy_at_goal:to_map()
                         --- Give massive penalty for this goal hex
                         cost = cost + 100
                     end
diff --git a/data/ai/micro_ais/cas/ca_healer_move.lua b/data/ai/micro_ais/cas/ca_healer_move.lua
index 68b2b2c45c95..5e746862e1f8 100644
--- a/data/ai/micro_ais/cas/ca_healer_move.lua
+++ b/data/ai/micro_ais/cas/ca_healer_move.lua
@@ -38,7 +38,7 @@ function ca_healer_move:evaluation(cfg, data)
         -- Potential healees are units without MP that don't already have a healer (also without MP) next to them
         -- Also, they cannot be on a village or regenerate
         if (healee.moves == 0) then
-            if (not wesnoth.match_unit(healee, { ability = "regenerates" })) then
+            if (not healee:matches { ability = "regenerates" }) then
                 local is_village = wesnoth.get_terrain_info(wesnoth.get_terrain(healee.x, healee.y)).village
                 if (not is_village) then
                     local is_healee = true
@@ -57,9 +57,9 @@ function ca_healer_move:evaluation(cfg, data)
     end
 
     local enemies = AH.get_attackable_enemies()
-    for _,healee in ipairs(healees_MP) do wesnoth.extract_unit(healee) end
+    for _,healee in ipairs(healees_MP) do healee:extract() end
     local enemy_attack_map = BC.get_attack_map(enemies)
-    for _,healee in ipairs(healees_MP) do wesnoth.put_unit(healee) end
+    for _,healee in ipairs(healees_MP) do healee:to_map() end
 
     local avoid_map = LS.of_pairs(ai.aspects.avoid)
 
@@ -106,7 +106,7 @@ function ca_healer_move:evaluation(cfg, data)
                 local is_village = wesnoth.get_terrain_info(wesnoth.get_terrain(loc[1], loc[2])).village
                 if is_village then rating = rating + 2 end
 
-                local defense = 100 - wesnoth.unit_defense(healer, wesnoth.get_terrain(loc[1], loc[2]))
+                local defense = 100 - healer:defense(wesnoth.get_terrain(loc[1], loc[2]))
                 rating = rating + defense / 10.
             end
 
diff --git a/data/ai/micro_ais/cas/ca_herding_sheep_move.lua b/data/ai/micro_ais/cas/ca_herding_sheep_move.lua
index 1fb0adaac2c9..2a8e1b079544 100644
--- a/data/ai/micro_ais/cas/ca_herding_sheep_move.lua
+++ b/data/ai/micro_ais/cas/ca_herding_sheep_move.lua
@@ -29,7 +29,7 @@ function ca_herding_sheep_move:execution(cfg)
     reach_map:iter( function(x, y, v)
         for xa, ya in H.adjacent_tiles(x, y) do
             local dog = wesnoth.get_unit(xa, ya)
-            if dog and (wesnoth.match_unit(dog, dogs_filter)) then
+            if dog and dog:matches(dogs_filter) then
                 reach_map:remove(x, y)
             end
         end
diff --git a/data/ai/micro_ais/cas/ca_messenger_move.lua b/data/ai/micro_ais/cas/ca_messenger_move.lua
index 1a395db244e9..0b91e2ceb183 100644
--- a/data/ai/micro_ais/cas/ca_messenger_move.lua
+++ b/data/ai/micro_ais/cas/ca_messenger_move.lua
@@ -57,21 +57,21 @@ function ca_messenger_move:execution(cfg)
 
     local unit_in_way = wesnoth.get_unit(next_hop[1], next_hop[2])
     if (unit_in_way == messenger) then unit_in_way = nil end
-    if unit_in_way then wesnoth.extract_unit(unit_in_way) end
+    if unit_in_way then unit_in_way:extract() end
 
     wesnoth.put_unit(messenger, next_hop[1], next_hop[2])
     local _, cost1 = AH.find_path_with_shroud(messenger, x, y, { ignore_units = 'yes' })
 
     local unit_in_way2 = wesnoth.get_unit(optimum_hop[1], optimum_hop[2])
     if (unit_in_way2 == messenger) then unit_in_way2 = nil end
-    if unit_in_way2 then wesnoth.extract_unit(unit_in_way2) end
+    if unit_in_way2 then unit_in_way2:extract() end
 
     wesnoth.put_unit(messenger, optimum_hop[1], optimum_hop[2])
     local _, cost2 = AH.find_path_with_shroud(messenger, x, y, { ignore_units = 'yes' })
 
     wesnoth.put_unit(messenger, x_current, y_current)
-    if unit_in_way then wesnoth.put_unit(unit_in_way) end
-    if unit_in_way2 then wesnoth.put_unit(unit_in_way2) end
+    if unit_in_way then unit_in_way:to_map() end
+    if unit_in_way2 then unit_in_way2:to_map() end
 
     -- If cost2 is significantly less, that means that the optimum path might
     -- overall be faster even though it is currently blocked
diff --git a/data/ai/micro_ais/cas/ca_protect_unit_move.lua b/data/ai/micro_ais/cas/ca_protect_unit_move.lua
index f86a72497b2b..2b72380ea411 100644
--- a/data/ai/micro_ais/cas/ca_protect_unit_move.lua
+++ b/data/ai/micro_ais/cas/ca_protect_unit_move.lua
@@ -23,7 +23,7 @@ function ca_protect_unit_move:execution(cfg, data)
 
     -- Need to take the protected units off the map, as they don't count into the map scores
     -- as long as they can still move
-    for _,unit in ipairs(protected_units) do wesnoth.extract_unit(unit) end
+    for _,unit in ipairs(protected_units) do unit:extract() end
 
     local units = wesnoth.get_units { side = wesnoth.current.side }
     local enemy_units = AH.get_attackable_enemies()
@@ -32,7 +32,7 @@ function ca_protect_unit_move:execution(cfg, data)
     local enemy_attack_map = BC.get_attack_map(enemy_units).units  -- enemy attack map
 
     -- Now put the protected units back out there
-    for _,unit in ipairs(protected_units) do wesnoth.put_unit(unit) end
+    for _,unit in ipairs(protected_units) do unit:to_map() end
 
     -- We move the weakest (fewest HP unit) first
     local unit = AH.choose(protected_units, function(u) return - u.hitpoints end)
@@ -46,7 +46,7 @@ function ca_protect_unit_move:execution(cfg, data)
 
     local terrain_defense_map = LS.create()
     reach_map:iter(function(x, y, data)
-        terrain_defense_map:insert(x, y, 100 - wesnoth.unit_defense(unit, wesnoth.get_terrain(x, y)))
+        terrain_defense_map:insert(x, y, 100 - unit:defense(wesnoth.get_terrain(x, y)))
     end)
 
     local goal_distance_map = LS.create()
diff --git a/data/ai/micro_ais/cas/ca_stationed_guardian.lua b/data/ai/micro_ais/cas/ca_stationed_guardian.lua
index ebb7890ab9c4..f8e0e6bcaf30 100644
--- a/data/ai/micro_ais/cas/ca_stationed_guardian.lua
+++ b/data/ai/micro_ais/cas/ca_stationed_guardian.lua
@@ -59,7 +59,7 @@ function ca_stationed_guardian:execution(cfg)
             if (not AH.is_visible_unit(wesnoth.current.side, unit_in_way))
                 or (unit_in_way == guardian)
             then
-                local defense = 100 - wesnoth.unit_defense(guardian, wesnoth.get_terrain(xa, ya))
+                local defense = 100 - guardian:defense(wesnoth.get_terrain(xa, ya))
                 local nh = AH.next_hop(guardian, xa, ya)
                 if nh then
                     if (nh[1] == xa) and (nh[2] == ya) and (defense > best_defense) then
diff --git a/data/ai/micro_ais/cas/ca_zone_guardian.lua b/data/ai/micro_ais/cas/ca_zone_guardian.lua
index 7216a472461d..b65391602158 100644
--- a/data/ai/micro_ais/cas/ca_zone_guardian.lua
+++ b/data/ai/micro_ais/cas/ca_zone_guardian.lua
@@ -46,7 +46,7 @@ function ca_zone_guardian:execution(cfg)
                 if (not AH.is_visible_unit(wesnoth.current.side, unit_in_way))
                     or (unit_in_way == guardian)
                 then
-                    local defense = 100 - wesnoth.unit_defense(guardian, wesnoth.get_terrain(xa, ya))
+                    local defense = 100 - guardian:defense(wesnoth.get_terrain(xa, ya))
                     local nh = AH.next_hop(guardian, xa, ya)
                     if nh then
                         if (nh[1] == xa) and (nh[2] == ya) and (defense > best_defense) then
diff --git a/data/campaigns/The_Rise_Of_Wesnoth/ai/ca_aggressive_attack_no_suicide.lua b/data/campaigns/The_Rise_Of_Wesnoth/ai/ca_aggressive_attack_no_suicide.lua
index e5aa18fce91c..aec1011dbc65 100644
--- a/data/campaigns/The_Rise_Of_Wesnoth/ai/ca_aggressive_attack_no_suicide.lua
+++ b/data/campaigns/The_Rise_Of_Wesnoth/ai/ca_aggressive_attack_no_suicide.lua
@@ -22,7 +22,7 @@ function ca_aggressive_attack_no_suicide:evaluation(cfg, data)
         local attacker = wesnoth.get_unit(att.src.x, att.src.y)
         local defender = wesnoth.get_unit(att.target.x, att.target.y)
 
-        local attacker_dst = wesnoth.copy_unit(attacker)
+        local attacker_dst = attacker:clone()
         attacker_dst.x, attacker_dst.y = att.dst.x, att.dst.y
 
         local att_stats, def_stats = wesnoth.simulate_combat(attacker_dst, defender)