diff --git a/Gemfile b/Gemfile
new file mode 100644
index 0000000..32c9c3e
--- /dev/null
+++ b/Gemfile
@@ -0,0 +1,4 @@
+# A sample Gemfile
+source "https://rubygems.org"
+
+gem "rspec"
diff --git a/Gemfile.lock b/Gemfile.lock
new file mode 100644
index 0000000..a8657ed
--- /dev/null
+++ b/Gemfile.lock
@@ -0,0 +1,26 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    diff-lcs (1.3)
+    rspec (3.6.0)
+      rspec-core (~> 3.6.0)
+      rspec-expectations (~> 3.6.0)
+      rspec-mocks (~> 3.6.0)
+    rspec-core (3.6.0)
+      rspec-support (~> 3.6.0)
+    rspec-expectations (3.6.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.6.0)
+    rspec-mocks (3.6.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.6.0)
+    rspec-support (3.6.0)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  rspec
+
+BUNDLED WITH
+   1.15.1
diff --git a/lib/ruby-dev-challenge/challenge_1.md b/lib/ruby-dev-challenge/challenge_1.md
new file mode 100644
index 0000000..8952454
--- /dev/null
+++ b/lib/ruby-dev-challenge/challenge_1.md
@@ -0,0 +1,14 @@
+# Desafio 1
+
+> O que esta expressão retorna e por quê?
+> 
+> `true and 0 && !nil and 3 > 2`
+
+A expressão acima retorna `true`, pois é uma sequência de `and`s onde todos os valores são avaliados para `true`.
+Simplificando a expressão:
+
+```ruby
+true and true && true and true
+```
+
+Neste caso, `and` e `&&` podem ser tratados como equivalentes. O que leva ao resultado `true`.
diff --git a/lib/ruby-dev-challenge/challenge_2.md b/lib/ruby-dev-challenge/challenge_2.md
new file mode 100644
index 0000000..c0844ec
--- /dev/null
+++ b/lib/ruby-dev-challenge/challenge_2.md
@@ -0,0 +1,14 @@
+# Desafio 2
+
+> Explique o funcionamento do operador _Or Equals_
+> 
+> `a ||= b`
+
+O operador _Or_Equals_, na expressão `a ||= b` faz com que ela seja equivalente à expressão `a || a = b`.
+Isso é utilizado para tirar proveito de que o operador `||` é _lazy_. Sendo assim, caso _a_ seja logicamente verdadeiro, mantém o seu valor. Mas se _a_ é logicamente falso, recebe o valor da expressão do lado direito do operador.
+
+Um exemplo de uso do operador é garantir que uma variável tenha um valor sempre:
+
+```ruby
+name ||= "Default Name"
+```
diff --git a/lib/ruby-dev-challenge/challenge_3/dev_magic.rb b/lib/ruby-dev-challenge/challenge_3/dev_magic.rb
new file mode 100644
index 0000000..5d7abd5
--- /dev/null
+++ b/lib/ruby-dev-challenge/challenge_3/dev_magic.rb
@@ -0,0 +1,22 @@
+class DevMagic
+  class << self
+    def print(number)
+      result = String.new
+
+      result << "Dev" if dev?(number)
+      result << "Magic" if magic?(number)
+      result << number.to_s if result.empty?
+      result
+    end
+
+    private
+
+    def dev?(number)
+      number % 3 == 0
+    end
+
+    def magic?(number)
+      number % 5 == 0
+    end
+  end
+end
diff --git a/lib/ruby-dev-challenge/challenge_3/script.rb b/lib/ruby-dev-challenge/challenge_3/script.rb
new file mode 100644
index 0000000..db7a4cf
--- /dev/null
+++ b/lib/ruby-dev-challenge/challenge_3/script.rb
@@ -0,0 +1,5 @@
+require 'dev_magic'
+
+(1..100).each do |n|
+  p DevMagic.print(n)
+end
diff --git a/lib/ruby-dev-challenge/challenge_4.rb b/lib/ruby-dev-challenge/challenge_4.rb
new file mode 100644
index 0000000..60d4ef5
--- /dev/null
+++ b/lib/ruby-dev-challenge/challenge_4.rb
@@ -0,0 +1,9 @@
+module Extensions
+  module String
+    module Palindrome
+      def palindrome?
+        self == self.reverse
+      end
+    end
+  end
+end
diff --git a/lib/ruby-dev-challenge/challenge_5.rb b/lib/ruby-dev-challenge/challenge_5.rb
new file mode 100644
index 0000000..417c7b9
--- /dev/null
+++ b/lib/ruby-dev-challenge/challenge_5.rb
@@ -0,0 +1,15 @@
+class IntegerConverter
+  class << self
+    def to_string(number)
+      validate(number)
+
+      "#{ number }" 
+    end
+
+    private
+
+    def validate(number)
+      raise ArgumentError unless number.is_a? Integer 
+    end
+  end
+end
diff --git a/spec/challenge_3_spec.rb b/spec/challenge_3_spec.rb
new file mode 100644
index 0000000..d8dffa2
--- /dev/null
+++ b/spec/challenge_3_spec.rb
@@ -0,0 +1,37 @@
+require './lib/ruby-dev-challenge/challenge_3/dev_magic'
+
+describe DevMagic do
+  subject { DevMagic.print(number) }
+
+  context "regular number" do
+    let(:number) { [ 1, 2, 4, 7 ].sample }
+
+    it "prints the number" do
+      is_expected.to eq number.to_s
+    end
+  end
+
+  context "divisible by 3" do
+    let(:number) { [ 3, 6, 9, 12 ].sample }
+
+    it "prints dev" do
+      is_expected.to eq "Dev"
+    end
+  end
+
+  context "divisible by 5" do
+    let(:number) { [ 5, 10, 20, 25 ].sample }
+
+    it "prints dev" do
+      is_expected.to eq "Magic"
+    end
+  end
+
+  context "divisible by both" do
+    let(:number) { [ 15, 30, 45, 60 ].sample }
+
+    it "prints dev" do
+      is_expected.to eq "DevMagic"
+    end
+  end
+end
diff --git a/spec/challenge_4_spec.rb b/spec/challenge_4_spec.rb
new file mode 100644
index 0000000..a7fb091
--- /dev/null
+++ b/spec/challenge_4_spec.rb
@@ -0,0 +1,15 @@
+require './lib/ruby-dev-challenge/challenge_4'
+
+String.include Extensions::String::Palindrome
+
+describe "a" do
+  it { is_expected.to be_palindrome }
+end
+
+describe "girafarig" do
+  it { is_expected.to be_palindrome }
+end
+
+describe "devMagic" do
+  it { is_expected.not_to be_palindrome }
+end
diff --git a/spec/challenge_5_spec.rb b/spec/challenge_5_spec.rb
new file mode 100644
index 0000000..9b0bbee
--- /dev/null
+++ b/spec/challenge_5_spec.rb
@@ -0,0 +1,19 @@
+require './lib/ruby-dev-challenge/challenge_5'
+
+describe IntegerConverter do
+  subject(:convert) { IntegerConverter.to_string(number) }
+
+  context "given a number" do
+    let(:number) { rand(100) }
+
+    it { is_expected.to eq number.to_s }
+  end
+
+  context "given an invalid input" do
+    let(:number) { nil }
+
+    it "throws an exception" do
+      expect { convert }.to raise_error ArgumentError
+    end
+  end
+end