diff --git a/.rspec b/.rspec
new file mode 100644
index 00000000..c99d2e73
--- /dev/null
+++ b/.rspec
@@ -0,0 +1 @@
+--require spec_helper
diff --git a/Gemfile b/Gemfile
new file mode 100644
index 00000000..41df210d
--- /dev/null
+++ b/Gemfile
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+source "https://rubygems.org"
+
+# gem "rails"
+
+gem "rspec", "~> 3.12"
diff --git a/Gemfile.lock b/Gemfile.lock
new file mode 100644
index 00000000..f29091b3
--- /dev/null
+++ b/Gemfile.lock
@@ -0,0 +1,26 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    diff-lcs (1.5.0)
+    rspec (3.12.0)
+      rspec-core (~> 3.12.0)
+      rspec-expectations (~> 3.12.0)
+      rspec-mocks (~> 3.12.0)
+    rspec-core (3.12.2)
+      rspec-support (~> 3.12.0)
+    rspec-expectations (3.12.3)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.12.0)
+    rspec-mocks (3.12.5)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.12.0)
+    rspec-support (3.12.0)
+
+PLATFORMS
+  arm64-darwin-22
+
+DEPENDENCIES
+  rspec (~> 3.12)
+
+BUNDLED WITH
+   2.4.11
diff --git a/lib/bowling_game.rb b/lib/bowling_game.rb
new file mode 100644
index 00000000..4f9e15a9
--- /dev/null
+++ b/lib/bowling_game.rb
@@ -0,0 +1,80 @@
+class BowlingGame
+  def initialize
+    @rolls = []
+  end
+
+
+  def roll(pins)
+    @rolls.push pins
+  end
+
+
+  def score
+    result = 0
+    rolls_count = 0
+
+    10.times do 
+      if strike(rolls_count)
+        result += strikeScore(rolls_count)
+        rolls_count += 1
+      elsif spare(rolls_count)
+        result += spareScore(rolls_count)
+        rolls_count += 2
+      else
+        result += frame(rolls_count)
+        rolls_count += 2
+      end
+    end
+    result
+  end
+
+
+  def frame(rolls_count)
+    @rolls[rolls_count] + @rolls[rolls_count + 1] 
+  end
+
+
+  def spare(rolls_count)
+    @rolls[rolls_count] + @rolls[rolls_count + 1] == 10
+  end
+
+
+  def spareScore(rolls_count)
+    10 + @rolls[rolls_count + 2]
+  end
+
+
+  def strike(rolls_count)
+    @rolls[rolls_count] == 10
+  end
+
+
+  def strikeScore(rolls_count)
+    10 + @rolls[rolls_count + 1] + @rolls[rolls_count + 2]
+  end
+end
+
+# def score
+#     result = 0
+#     rolls_count = 0
+
+#     # 20.times do # 20 = no of rolls in 10 frames
+#     #   result += @rolls[rolls_count]
+#     #   rolls_count += 1
+#     # the above 3 lines counts the score by roll. to refactor, we will count by frame next as follows:
+
+#     10.times do # no of frames
+#       if @rolls[rolls_count] == 10 # if strike
+#         result += @rolls[rolls_count] + @rolls[rolls_count + 1] + @rolls[rolls_count + 2] # add 10 + the next 2 rolls
+#         rolls_count += 1 # 1 roll has been added, move onto next frame
+
+#       elsif @rolls[rolls_count] + @rolls[rolls_count + 1] == 10 # if the first and second roll [+1] is equal to 10
+#         result += @rolls[rolls_count] + @rolls[rolls_count + 1] + @rolls[rolls_count + 2] # then add the next roll twice to the result
+#         rolls_count += 2 # 2 rolls have been added, move onto next frame
+
+#       elsif result += @rolls[rolls_count] + @rolls[rolls_count + 1] # frame = 2 rolls
+#         rolls_count += 2 # 2 rolls have been added, move onto next frame
+#       end
+#     end
+#     result
+#   end
diff --git a/spec/bowling_game_spec.rb b/spec/bowling_game_spec.rb
new file mode 100644
index 00000000..816d98fc
--- /dev/null
+++ b/spec/bowling_game_spec.rb
@@ -0,0 +1,76 @@
+require 'bowling_game'
+
+describe BowlingGame do
+  # reafctoring: to avoid initializing 'game' via BowlingGame.new, we can call it with @ via:
+
+  before do
+    @game = BowlingGame.new
+  end
+
+  context 'creates and plays a bowling game with 1 player' do
+    it 'creates game' do
+      @game # initializes game/class
+    end
+  end
+
+  it 'rolls a gutter game, 20 rolls with no pins knocked over' do
+    20.times { @game.roll 0 }
+    expect(@game.score).to eq 0
+  end
+
+  it 'can roll and knock just 1 pin 20 times' do
+    20.times { @game.roll 1 }
+    expect(@game.score).to eq 20
+  end
+
+  it 'add two rolls in a frame if under 10 pins' do
+    @game.roll 1
+    @game.roll 4
+    18.times { @game.roll 0 }
+    expect(@game.score).to eq 5
+  end
+
+  it 'can roll a spare' do
+    @game.roll 6
+    @game.roll 4
+    @game.roll 5
+    17.times { @game.roll 0 }
+    expect(@game.score).to eq 20
+  end
+
+  it 'can roll a strike' do
+    @game.roll 10
+    @game.roll 2
+    @game.roll 3
+    16.times { @game.roll 0 }
+    expect(@game.score).to eq 20
+  end
+
+  it 'can roll a perfect game' do
+    12.times { @game.roll 10 }
+    expect(@game.score).to eq 300
+  end
+
+  it 'creates the example score of the exercise' do
+    @game.roll 1
+    @game.roll 4
+    @game.roll 4
+    @game.roll 5
+    @game.roll 6
+    @game.roll 4
+    @game.roll 5
+    @game.roll 5
+    @game.roll 10
+    @game.roll 0
+    @game.roll 1
+    @game.roll 7
+    @game.roll 3
+    @game.roll 6
+    @game.roll 4
+    @game.roll 10
+    @game.roll 2
+    @game.roll 8
+    @game.roll 6
+    expect(@game.score).to eq 133
+  end
+end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
new file mode 100644
index 00000000..c80d44b9
--- /dev/null
+++ b/spec/spec_helper.rb
@@ -0,0 +1,98 @@
+# This file was generated by the `rspec --init` command. Conventionally, all
+# specs live under a `spec` directory, which RSpec adds to the `$LOAD_PATH`.
+# The generated `.rspec` file contains `--require spec_helper` which will cause
+# this file to always be loaded, without a need to explicitly require it in any
+# files.
+#
+# Given that it is always loaded, you are encouraged to keep this file as
+# light-weight as possible. Requiring heavyweight dependencies from this file
+# will add to the boot time of your test suite on EVERY test run, even for an
+# individual file that may not need all of that loaded. Instead, consider making
+# a separate helper file that requires the additional dependencies and performs
+# the additional setup, and require it from the spec files that actually need
+# it.
+#
+# See https://rubydoc.info/gems/rspec-core/RSpec/Core/Configuration
+RSpec.configure do |config|
+  # rspec-expectations config goes here. You can use an alternate
+  # assertion/expectation library such as wrong or the stdlib/minitest
+  # assertions if you prefer.
+  config.expect_with :rspec do |expectations|
+    # This option will default to `true` in RSpec 4. It makes the `description`
+    # and `failure_message` of custom matchers include text for helper methods
+    # defined using `chain`, e.g.:
+    #     be_bigger_than(2).and_smaller_than(4).description
+    #     # => "be bigger than 2 and smaller than 4"
+    # ...rather than:
+    #     # => "be bigger than 2"
+    expectations.include_chain_clauses_in_custom_matcher_descriptions = true
+  end
+
+  # rspec-mocks config goes here. You can use an alternate test double
+  # library (such as bogus or mocha) by changing the `mock_with` option here.
+  config.mock_with :rspec do |mocks|
+    # Prevents you from mocking or stubbing a method that does not exist on
+    # a real object. This is generally recommended, and will default to
+    # `true` in RSpec 4.
+    mocks.verify_partial_doubles = true
+  end
+
+  # This option will default to `:apply_to_host_groups` in RSpec 4 (and will
+  # have no way to turn it off -- the option exists only for backwards
+  # compatibility in RSpec 3). It causes shared context metadata to be
+  # inherited by the metadata hash of host groups and examples, rather than
+  # triggering implicit auto-inclusion in groups with matching metadata.
+  config.shared_context_metadata_behavior = :apply_to_host_groups
+
+# The settings below are suggested to provide a good initial experience
+# with RSpec, but feel free to customize to your heart's content.
+=begin
+  # This allows you to limit a spec run to individual examples or groups
+  # you care about by tagging them with `:focus` metadata. When nothing
+  # is tagged with `:focus`, all examples get run. RSpec also provides
+  # aliases for `it`, `describe`, and `context` that include `:focus`
+  # metadata: `fit`, `fdescribe` and `fcontext`, respectively.
+  config.filter_run_when_matching :focus
+
+  # Allows RSpec to persist some state between runs in order to support
+  # the `--only-failures` and `--next-failure` CLI options. We recommend
+  # you configure your source control system to ignore this file.
+  config.example_status_persistence_file_path = "spec/examples.txt"
+
+  # Limits the available syntax to the non-monkey patched syntax that is
+  # recommended. For more details, see:
+  # https://rspec.info/features/3-12/rspec-core/configuration/zero-monkey-patching-mode/
+  config.disable_monkey_patching!
+
+  # This setting enables warnings. It's recommended, but in some cases may
+  # be too noisy due to issues in dependencies.
+  config.warnings = true
+
+  # Many RSpec users commonly either run the entire suite or an individual
+  # file, and it's useful to allow more verbose output when running an
+  # individual spec file.
+  if config.files_to_run.one?
+    # Use the documentation formatter for detailed output,
+    # unless a formatter has already been configured
+    # (e.g. via a command-line flag).
+    config.default_formatter = "doc"
+  end
+
+  # Print the 10 slowest examples and example groups at the
+  # end of the spec run, to help surface which specs are running
+  # particularly slow.
+  config.profile_examples = 10
+
+  # Run specs in random order to surface order dependencies. If you find an
+  # order dependency and want to debug it, you can fix the order by providing
+  # the seed, which is printed after each run.
+  #     --seed 1234
+  config.order = :random
+
+  # Seed global randomization in this process using the `--seed` CLI option.
+  # Setting this allows you to use `--seed` to deterministically reproduce
+  # test failures related to randomization by passing the same `--seed` value
+  # as the one that triggered the failure.
+  Kernel.srand config.seed
+=end
+end