diff --git a/2018/day15-input b/2018/day15-input
new file mode 100644
index 0000000..b5fdc94
--- /dev/null
+++ b/2018/day15-input
@@ -0,0 +1,32 @@
+################################
+###################........#####
+###################..G..#G..####
+####################........####
+##..G###############G......#####
+###..G###############.....######
+#####.######..######....G##..###
+#####.........####............##
+#########...#####.............##
+#########...####..............##
+#########E#####.......GE......##
+#########............E...G...###
+######.###....#####..G........##
+#.G#....##...#######.........###
+##.#....##GG#########.........##
+#....G#....E#########....#....##
+#...........#########.......####
+#####..G....#########...##....##
+#####....G..#########.#.......##
+#######...G..#######G.....#...##
+######....E...#####............#
+######...GG.......E......#...E.#
+#######.G...#....#..#...#.....##
+#######..........#####..####.###
+########.......E################
+#######..........###############
+########.............###########
+#########...#...##....##########
+#########.....#.#..E..##########
+################.....###########
+################.##E.###########
+################################
diff --git a/2018/day15.py b/2018/day15.py
new file mode 100644
index 0000000..7d5e008
--- /dev/null
+++ b/2018/day15.py
@@ -0,0 +1,219 @@
+with open('day15-input-dev', 'r') as file:
+  data = [l.strip('\n') for l in file]
+# data = [
+# '#######',
+# '#.G...#',
+# '#...EG#',
+# '#.#.#G#',
+# '#..G#E#',
+# '#.....#',
+# '#######',
+# ]
+import numpy as np
+from pathfinding.core.grid import Grid
+from pathfinding.finder.dijkstra import DijkstraFinder
+import sys
+
+grid = np.zeros((len(data), len(data[0])), dtype=np.int64)
+cells = {'#': 0, '.': 1, 'G': 1, 'E': 1}
+goblins = []
+elves = []
+starting_hp = 200
+starting_atk = 3
+starting_atk_elf = 29
+adjacent = np.array([[0,-1], [-1,0], [1,0], [0,1]], dtype=np.int64)
+enemy_teams = [goblins, elves]
+unit_positions = []
+pathfind_grid = None
+# pathfinder = AStarFinder()
+pathfinder = DijkstraFinder()
+UID = 0
+
+class Unit:
+  def __init__(self, x, y, starting_hp, atk, team):
+    global UID
+    self.team = team
+    self.atk = atk
+    self.hp = starting_hp
+    self.pos = np.array([x, y], dtype=np.int64)
+    self.uid = UID
+    UID += 1
+
+  def __eq__(self, other):
+    return self.uid == other.uid
+
+  @property
+  def x(self):
+    return self.pos[0]
+  @property
+  def y(self):
+    return self.pos[1]
+
+  def distance(self, pos):
+    return np.abs(pos - self.pos).sum()
+
+  def path_to(self, pos, exhaustive=False):
+    if not exhaustive:
+      pathfind_grid = Grid(matrix=grid2)
+      start = pathfind_grid.node(*tuple(self.pos))
+      end = pathfind_grid.node(*tuple(pos))
+      path, runs = pathfinder.find_path(start, end, pathfind_grid)
+      return path
+    else:
+      paths = []
+      for d in range(len(adjacent)):
+        try:
+          trystart = tuple(self.pos + adjacent[d])
+          if grid2[trystart] and trystart not in unit_positions:
+            pathfind_grid = Grid(matrix=grid2.T)
+            start = pathfind_grid.node(*trystart)
+            end = pathfind_grid.node(*tuple(pos))
+            path, runs = pathfinder.find_path(start, end, pathfind_grid)
+            # print(pathfind_grid.grid_str(path=path, start=start, end=end))
+            if len(path) > 0:
+              paths.append(path)
+        except Exception:
+          pass
+      if paths:
+        paths = sorted(paths, key=lambda x: len(x))
+        # print(paths)
+        return paths[0]
+      return []
+
+  def path_distance(self, pos):
+    return len(self.path_to(pos, True)) or 90000  # Sorting hack
+
+  def path_distance_and_priority(self, pos):
+    path = self.path_to(pos, True)
+    if path:
+      for i in range(len(adjacent)):
+        if path[0] == tuple(self.pos + adjacent[i]):
+          priority = i
+          break
+      return len(path), priority
+    return (90000, 90000)  # Sorting hack
+
+  def __repr__(self):
+    return f'[{"Elf" if not self.team else "Gob"}, Position {self.x},{self.y}, HP {self.hp}]'
+
+
+for y, row in enumerate(data):
+  for x, c in enumerate(row):
+    grid[x,y] = cells[c]
+    if c == 'E':
+      elves.append(Unit(x, y, starting_hp, starting_atk_elf, 0))
+    elif c == 'G':
+      goblins.append(Unit(x, y, starting_hp, starting_atk, 1))
+grid2 = grid.copy()
+
+def turn_sort(unit):
+  return unit.y, unit.x
+
+
+def target_sort(unit):
+  return unit.hp, unit.y, unit.x
+
+
+def do_round():
+  global unit_positions, pathfind_grid
+  combatants = sorted(goblins + elves, key=turn_sort)
+  i = 0
+  while i < len(combatants):
+    unit_positions = [tuple(u.pos) for u in combatants]
+    grid2[:] = grid[:]
+    for p in unit_positions:
+      grid2[p] = -1
+    unit = combatants[i]
+    i += 1
+    enemy_team = enemy_teams[unit.team]
+
+    # If no enemies left, end combat
+    if len(enemy_team) == 0:
+      return
+
+    # If adjacent to an enemy, attack it
+    adjacent_enemies = []
+    for enemy in enemy_team:
+      if unit.distance(enemy.pos) == 1:
+        adjacent_enemies.append(enemy)
+    if adjacent_enemies:
+      # print(sorted(adjacent_enemies, key=target_sort))
+      target = sorted(adjacent_enemies, key=target_sort)[0]
+      # print(f'Unit #{unit.uid} attacking unit {target.uid}')
+      target.hp -= unit.atk
+      if target.hp <= 0:
+        if target.team == 0:
+          print('Elf died, aborting!')
+          sys.exit(1)
+        enemy_team.remove(target)
+        j = combatants.index(target)
+        combatants.pop(j)
+        if j < i:
+          i -= 1
+      continue
+
+    # Find all cells to move to
+    target_cells = {tuple(t.pos + adjacent[j]) for t in enemy_team for j in range(4)}
+    target_cells = {c for c in target_cells if grid[c] == 1 and c not in unit_positions}
+    target_cells = sorted([np.array(c) for c in target_cells], key=lambda x: unit.path_distance_and_priority(x))
+    # Move to closest target cell
+    if target_cells:
+      path = unit.path_to(target_cells[0], exhaustive=True)
+      if path:
+        # print(f'Unit #{unit.uid} moving from {unit.pos} to {path[0]}')
+        unit.pos[:] = path[0]
+      else:
+        pass
+        # print(f'Unit #{unit.uid} cannot move!')
+
+    # If adjacent to an enemy, attack it
+    adjacent_enemies = []
+    for enemy in enemy_team:
+      if unit.distance(enemy.pos) == 1:
+        adjacent_enemies.append(enemy)
+    if adjacent_enemies:
+      target = sorted(adjacent_enemies, key=target_sort)[0]
+      # print(f'Unit #{unit.uid} attacking unit {target.uid}')
+      target.hp -= unit.atk
+      if target.hp <= 0:
+        enemy_team.remove(target)
+        j = combatants.index(target)
+        combatants.pop(j)
+        if j < i:
+          i -= 1
+      continue
+
+def print_state():
+  char_array = np.zeros_like(grid)
+  char_array[(grid == 0)] = ord('#')
+  char_array[(grid == 1)] = ord('.')
+  unit_strs = [[] for i in range(len(char_array))]
+  for g in goblins:
+    char_array[g.x, g.y] = ord('G')
+    unit_strs[g.y].append((f'G({g.hp})', g.x))
+  for e in elves:
+    char_array[e.x, e.y] = ord('E')
+    unit_strs[e.y].append((f'E({e.hp})', e.x))
+  for row in range(len(char_array)):
+    maprow =''.join([chr(c) for c in char_array.T[row]])
+    unithps = ', '.join([s[0] for s in sorted(unit_strs[row], key=lambda x: x[1])])
+    print(maprow, unithps)
+
+
+
+def do_exterminatus(quit_after=9999999):
+  rounds = 0
+  while len(goblins) and len(elves) and rounds < quit_after:
+    print(f'Round #{rounds}')
+    print_state()
+    do_round()
+    rounds += 1
+  return rounds
+
+
+round = do_exterminatus()
+if goblins:
+  num = sum(u.hp for u in goblins)
+else:
+  num = sum(u.hp for u in elves)
+print(round, num, round*num)