This is a horribly contrived example of a set of specs that only pass if run in the order they're presented. They'll fail if run in the opposite order.

ordered_spec.rb

require 'spec_helper'

describe 'unintended sequence' do
  before(:all) do 
    @x = {a: 1, b: 2}
  end

  it 'modifies the array' do
    @x[:a] = 2
    @x[:a].should eq 2
  end

  it 'checks the array' do
    @x[:a].should eq 2
  end
end