Solution to every level of RubyWarrior (https://www.bloc.io/ruby-warrior/#/). Heavily borrowed from https://gist.github.com/jnf/6198927

warrior.rb

# N.B. doesn't get maximum score: 
# * won't get captives behind the warrior
# * will shoot captives at look[1] if an enemy is in look[2]

class Player
  def play_turn(warrior)
    @warrior      = warrior
    ## uncomment `@max_health` and `@prev_health` on level 3
    # @max_health  ||= warrior.health # set to `1` to complete level 8 in 27 turns
    # @prev_health ||= @max_health
    ## uncomment `@space` on level 2
    # @space        = @warrior.feel
    
    feel_it_out
    
    ## uncomment this line on level 3
    # @prev_health = warrior.health
  end
  
  protected
  
  def feel_it_out
    ## uncomment `about_face` on level 7
    # return about_face       if @space.wall?
    ## uncomment `be_a_hero` on level 5
    # return be_a_hero        if @space.captive?
    ## uncomment `strike` on level 2
    # return strike           if @space.enemy?
    ## uncomment `ddos` on level 8
    # return ddos             if @warrior.look[2].enemy?
    ## uncomment `reconsider` on level 4
    # return reconsider       if @warrior.health < @prev_health
    ## uncomment `sleep_it_off` on level 3
    # return sleep_it_off     if @space.empty? and (@warrior.health < @max_health)
    return move
  end
  
  def sleep_it_off
    @warrior.rest!
  end
  
  def strike
    @warrior.attack!
  end
  
  def ddos
    @warrior.shoot!
  end
  
  def move(direction = :forward)
    @warrior.walk! direction
  end
  
  def be_a_hero
    @warrior.rescue!
  end
  
  def about_face
    @warrior.pivot!
  end
  
  def reconsider
    move(@warrior.health < (@max_health / 4) ? :backward : :forward)
  end
end