The Conditional Rules Administration screen let you setup expression that you can apply on 

• Approval Mappings and Single Issue Approval, in order to require the approvals only if the condition returns true or let transition the issue if the condition returns true depending by the number of approbations or rejections

• Approval E-mail Templates, in order to send emails with priority high when the condition returns true.

Notice that you can reuse a Conditional Rule across different Approval Mappings, Single Issue Approval and Approval E-mail Templates.