This gem allows similar ActiveRecord validates_* commands to be grouped together in blocks and pruned of repeated parameters. How often have you had a block of validation commands in an ActiveRecord object that are repeated, especially :id or :unless options? Does this look familiar? validates_presence_of :hair, :hair_color, :unless => :bald? validates_length_of :hair, :within => 3..15, :unless => :bald? validates_inclusion_of :hair_color, :in => HAIR_COLORS, :unless => bald? Instead, this gem will allow you to replace the above code with: validate_block :unless => :bald? do presence_of :hair, :hair_color length_of :hair, :within => 3..15 inclusion_of :hair_color, :in => HAIR_COLORS end ..which is a great way to DRY your :hair, don't you think? Basically, this gem 1) removes the requirement to have 'validates_' on the front of the commands and 2) passes the options on the validate_block command to each validation command inside the block. The syntax of the validation commands remains the same. Keeping the 'validates_*' prefix on the commands inside the block _will_ work but it is not required.