Create a die-definition by creating an array containing a value for each side of the die. Can be used to generate statistical tables for personal use like https://docs.google.com/spreadsheets/d/1diclXxKa3jpCFKu91dWspjao72d_lEbHyT02spjRVQI/edit?usp=sharing

dice-faceoffs.rb

# d3 from the game 'Bord'
bd3 = [0, 1, 10]

# standard d3 & d6
d3 = [1,2,3]
d6 = [1,2,3,4,5,6]

# generates all possible totals for a given number of a given die-definition
def gen_totals(die, num_dice)
  gen_totals_helper(die, num_dice, [])
end

def gen_totals_helper(die, num_dice, global_totals)
  return global_totals[num_dice] unless global_totals[num_dice].nil?

  local_totals = []

  die.each do |die_side|
    if num_dice == 1
      local_totals << die_side
    else
      gen_totals(die, num_dice - 1).each do |total|
        local_totals << total + die_side
      end
    end
  end

  global_totals[num_dice] = local_totals.uniq.sort
end

# counts up all of the victories, losses, and draws between two homogenous pools of dice
#
# draw_victory: when true, draws will count as a victory. when false, draws count as a loss. when nil, draws are counted separately.
def faceoff_odds(roll_1_num_dice, roll_1_die, roll_2_num_dice, roll_2_die, draw_victory: nil)
  roll_1_totals = gen_totals(roll_1_die, roll_1_num_dice)
  roll_2_totals = gen_totals(roll_2_die, roll_2_num_dice)

  total_matchups = roll_1_totals.length * roll_2_totals.length
  victories = 0
  losses = 0
  draws = 0

  roll_1_totals.each do |roll_1_total|
    roll_2_totals.each do |roll_2_total|
      if roll_1_total > roll_2_total
        victories += 1
      elsif roll_1_total < roll_2_total
        losses += 1
      else
        case draw_victory
        when true
          victories += 1
        when false
          losses += 1
        else
          draws += 1
        end
      end
    end
  end

  { victories: victories, losses: losses, draws: draws, total_matchups: total_matchups }
end

# generates a 6x6 2d array of win/loss/draw data for 2 die-definitions
def gen_percentage_table(die_1, die_2, draw_victory: false)
  table = {}
  (1..6).each do |num_dice_1|
    table[num_dice_1] = {}
    (1..6).each do |num_dice_2|
      table[num_dice_1][num_dice_2] = faceoff_odds(num_dice_1, die_1, num_dice_2, die_2, draw_victory: draw_victory)
    end
  end
  table
end

# prints a table returned from `gen_percentage_table()` in markdown format 
def print_percentage_table(table)
  print '|-----|'
  (1..6).each do |i|
    print " #{i} |"
  end
  puts
  print '|-----|'
  (1..6).each do |i|
    print "-----|"
  end
  puts
  table.each do |num_dice_1, row|
    print "| #{num_dice_1} |"
    row.each do |num_dice_2, odds|
      print " #{ (odds[:victories] * 1.0  / odds[:total_matchups]).round(2) * 100 }% |"
    end
    puts
  end

  ''
end

# Example Usage
puts 'bd3'
puts print_percentage_table(gen_percentage_table(bd3, bd3)

puts 'd3'
puts print_percentage_table(gen_percentage_table(d3, d3, draw_victory: true)

puts 'd6'
puts print_percentage_table(gen_percentage_table(d6, d6, draw_victory: false)