diff --git a/.rubocop.yml b/.rubocop.yml
index 9fe6c64747..80144a1092 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -123,8 +123,6 @@ Rails/FilePath:
   Enabled: false
 Performance/UnfreezeString:
   Enabled: false
-Style/GuardClause:
-  Enabled: false
 Rails/HasManyOrHasOneDependent:
   Enabled: false
 Rails/InverseOf:
diff --git a/app/controllers/courses_controller.rb b/app/controllers/courses_controller.rb
index 49cbcf7ad5..9fea058313 100644
--- a/app/controllers/courses_controller.rb
+++ b/app/controllers/courses_controller.rb
@@ -408,13 +408,12 @@ def update_course_format
   def update_last_reviewed
     username = params.dig(:course, 'last_reviewed', 'username')
     timestamp = params.dig(:course, 'last_reviewed', 'timestamp')
-    if username && timestamp
-      @course.flags['last_reviewed'] = {
-        'username' => username,
-        'timestamp' => timestamp
-      }
-      @course.save
-    end
+    return unless username && timestamp
+    @course.flags['last_reviewed'] = {
+      'username' => username,
+      'timestamp' => timestamp
+    }
+    @course.save
   end
 
   def handle_post_course_creation_updates
diff --git a/app/controllers/requested_accounts_controller.rb b/app/controllers/requested_accounts_controller.rb
index 561651570b..a38740ac68 100644
--- a/app/controllers/requested_accounts_controller.rb
+++ b/app/controllers/requested_accounts_controller.rb
@@ -130,10 +130,9 @@ def passcode_valid?
 
   def handle_existing_request
     existing_request = RequestedAccount.find_by(course: @course, username: params[:username])
-    if existing_request
-      existing_request.update(email: params[:email])
-      render json: { message: existing_request.updated_email_message }
-      yield
-    end
+    return unless existing_request
+    existing_request.update(email: params[:email])
+    render json: { message: existing_request.updated_email_message }
+    yield
   end
 end
diff --git a/app/helpers/article_helper.rb b/app/helpers/article_helper.rb
index ae1ade0ce6..277b990fbe 100644
--- a/app/helpers/article_helper.rb
+++ b/app/helpers/article_helper.rb
@@ -35,25 +35,16 @@ def rating_priority(rating)
   def rating_display(rating)
     rating = default_class(rating)
     return nil if rating.nil?
-    if %w[fa ga fl].include? rating
-      return rating
-    else
-      return rating[0] # use the first letter of the rating as the abbreviated version
-    end
+    return rating if %w[fa ga fl].include? rating
+    return rating[0] # use the first letter of the rating as the abbreviated version
   end
 
   def default_class(rating)
     # Handles the different article classes and returns a known article class
-    if %w[fa fl a ga b c start stub list].include? rating
-      return rating
-    elsif rating.eql? 'bplus'
-      return 'b'
-    elsif rating.eql? 'a/ga'
-      return 'a'
-    elsif %w[al bl cl sl].include? rating
-      return 'list'
-    else
-      return nil
-    end
+    return rating if %w[fa fl a ga b c start stub list].include? rating
+    return 'b' if rating.eql? 'bplus'
+    return 'a' if rating.eql? 'a/ga'
+    return 'list' if %w[al bl cl sl].include? rating
+    return nil
   end
 end
diff --git a/app/models/campaign.rb b/app/models/campaign.rb
index bd5d147c0d..d7a6ef2a70 100644
--- a/app/models/campaign.rb
+++ b/app/models/campaign.rb
@@ -171,10 +171,9 @@ def valid_start_and_end_dates?
   def set_slug
     campaign_slug = slug.presence || title
     self.slug = campaign_slug.downcase
-    unless /^[\p{L}0-9_]+$/.match?(campaign_slug.downcase)
-      # Strip everything but unicode letters and digits, and convert spaces to underscores.
-      self.slug = campaign_slug.downcase.gsub(/[^\p{L}0-9 ]/, '').tr(' ', '_')
-    end
+    return if /^[\p{L}0-9_]+$/.match?(campaign_slug.downcase)
+    # Strip everything but unicode letters and digits, and convert spaces to underscores.
+    self.slug = campaign_slug.downcase.gsub(/[^\p{L}0-9 ]/, '').tr(' ', '_')
   end
 
   def set_default_times
diff --git a/app/services/add_sandbox_template.rb b/app/services/add_sandbox_template.rb
index e1f181e37b..7ee90a62ad 100644
--- a/app/services/add_sandbox_template.rb
+++ b/app/services/add_sandbox_template.rb
@@ -19,13 +19,8 @@ def initialize(home_wiki:, sandbox:, sandbox_template:, current_user:)
 
   def add_template
     # Never double-post the sandbox template
-    if sandbox_template_present?
-      return
-    elsif default_template_present?
-      replace_default_with_sandbox_template
-    else
-      add_sandbox_template
-    end
+    return if sandbox_template_present?
+    default_template_present? ? replace_default_with_sandbox_template : add_sandbox_template
   end
 
   def sandbox_template_present?
diff --git a/app/services/sandbox_url_updator.rb b/app/services/sandbox_url_updator.rb
index 2921a5e883..bc7dd4ac64 100644
--- a/app/services/sandbox_url_updator.rb
+++ b/app/services/sandbox_url_updator.rb
@@ -32,8 +32,11 @@ def validate_new_url
     raise InvalidUrlError, I18n.t('assignments.invalid_url', url: @new_url) unless new_url_match
     # Handle mismatched wiki
     new_language, new_project = new_url_match.captures
-    unless existing_language == new_language && existing_project == new_project
-      raise MismatchedWikiError, I18n.t('assignments.mismatched_wiki', url: @new_url)
-    end
+    wiki_matches = (existing_language == new_language && existing_project == new_project)
+    handle_mismatched_wiki unless wiki_matches
+  end
+
+  def handle_mismatched_wiki
+    raise MismatchedWikiError, I18n.t('assignments.mismatched_wiki', url: @new_url)
   end
 end
diff --git a/lib/assignment_manager.rb b/lib/assignment_manager.rb
index 313cec6422..d1bd7af70f 100644
--- a/lib/assignment_manager.rb
+++ b/lib/assignment_manager.rb
@@ -107,10 +107,12 @@ def set_article_from_database
 
   def check_wiki_edu_discouraged_article
     category = Category.find_by(name: ENV['blocked_assignment_category'])
+    article_discouraged = (category.present? && category.article_titles.include?(@clean_title))
+    handle_discouraged_article if article_discouraged
+  end
 
-    if category.present? && category.article_titles.include?(@clean_title)
-      raise DiscouragedArticleError, I18n.t('assignments.blocked_assignment', title: @clean_title)
-    end
+  def handle_discouraged_article
+    raise DiscouragedArticleError, I18n.t('assignments.blocked_assignment', title: @clean_title)
   end
 
   def import_article_from_wiki
diff --git a/lib/list_course_manager.rb b/lib/list_course_manager.rb
index e541424eac..0208b9de11 100644
--- a/lib/list_course_manager.rb
+++ b/lib/list_course_manager.rb
@@ -39,12 +39,11 @@ def add_instructor_real_names
 
   def add_classroom_program_manager_if_exists
     cpm = SpecialUsers.classroom_program_manager
-    if cpm && @course.type == 'ClassroomProgramCourse'
-      CoursesUsers.create(user: cpm,
-                          course: @course,
-                          role: CoursesUsers::Roles::WIKI_ED_STAFF_ROLE,
-                          real_name: cpm.real_name)
-    end
+    return unless cpm && @course.type == 'ClassroomProgramCourse'
+    CoursesUsers.create(user: cpm,
+                        course: @course,
+                        role: CoursesUsers::Roles::WIKI_ED_STAFF_ROLE,
+                        real_name: cpm.real_name)
   end
 
   def send_approval_notification_emails
diff --git a/lib/reference_counter_api.rb b/lib/reference_counter_api.rb
index cd51cb023b..b70d79e44d 100644
--- a/lib/reference_counter_api.rb
+++ b/lib/reference_counter_api.rb
@@ -56,15 +56,12 @@ def get_number_of_references_from_revision_id(rev_id)
     tries ||= 5
     response = toolforge_server.get(references_query_url(rev_id))
     parsed_response = Oj.load(response.body)
-    if response.status == 200
-      return { 'num_ref' => parsed_response['num_ref'] }
-    else
-      # Log the error and return empty hash
-      # Sentry.capture_message 'Non-200 response hitting references counter API', level: 'warning',
-      # extra: { project_code: @project_code, language_code: @language_code, rev_id:,
-      #                        status_code: response.status, content: parsed_response }
-      return { 'num_ref' => nil }
-    end
+    return { 'num_ref' => parsed_response['num_ref'] } if response.status == 200
+    # Log the error and return empty hash
+    # Sentry.capture_message 'Non-200 response hitting references counter API', level: 'warning',
+    # extra: { project_code: @project_code, language_code: @language_code, rev_id:,
+    #                        status_code: response.status, content: parsed_response }
+    return { 'num_ref' => nil }
   rescue StandardError => e
     tries -= 1
     retry unless tries.zero?
diff --git a/lib/revision_feedback_service.rb b/lib/revision_feedback_service.rb
index 356b426ee1..fbba09f3a9 100644
--- a/lib/revision_feedback_service.rb
+++ b/lib/revision_feedback_service.rb
@@ -19,9 +19,8 @@ def feedback
   def citation_feedback
     ref_tags = @features['feature.wikitext.revision.ref_tags']
     # cite_templates = @features['feature.enwiki.revision.cite_templates']
-    if ref_tags < MINIMUM_REFERENCES
-      @feedback << 'Cite your sources! This article needs more references.'
-    end
+    return unless ref_tags < MINIMUM_REFERENCES
+    @feedback << 'Cite your sources! This article needs more references.'
   end
 
   # The largest reasonable average section size, calculated from content characters
diff --git a/lib/revision_score_api_handler.rb b/lib/revision_score_api_handler.rb
index 5cfc9c757f..8d9a8973d1 100644
--- a/lib/revision_score_api_handler.rb
+++ b/lib/revision_score_api_handler.rb
@@ -14,9 +14,8 @@ def initialize(language: 'en', project: 'wikipedia', wiki: nil, update_service:
     # Initialize LiftWingApi if the wiki is valid for it
     @lift_wing_api = LiftWingApi.new(@wiki, @update_service) if LiftWingApi.valid_wiki?(@wiki)
     # Initialize ReferenceCounterApi if the wiki is valid for it
-    if ReferenceCounterApi.valid_wiki?(@wiki)
-      @reference_counter_api = ReferenceCounterApi.new(@wiki, @update_service)
-    end
+    return unless ReferenceCounterApi.valid_wiki?(@wiki)
+    @reference_counter_api = ReferenceCounterApi.new(@wiki, @update_service)
   end
 
   # Returns data from LiftWing API and/or reference-counter API.
diff --git a/lib/training_module_due_date_manager.rb b/lib/training_module_due_date_manager.rb
index cba43334dc..178878a316 100644
--- a/lib/training_module_due_date_manager.rb
+++ b/lib/training_module_due_date_manager.rb
@@ -49,11 +49,8 @@ def module_progress
 
   def flags(course_id)
     flags_hash = @tmu&.flags
-    if @training_module.exercise? && flags_hash.present?
-      return flags_hash[course_id] || flags_hash
-    else
-      return flags_hash
-    end
+    return flags_hash[course_id] || flags_hash if @training_module.exercise? && flags_hash.present?
+    return flags_hash
   end
 
   def sandbox_url