Synopsis As Introduced Proposes to amend the Legislature and Finance Articles of the Illinois Constitution. Amends the Finance Article to provide that the State budget shall be based on estimated revenue (now funds); defines "revenue". Provides that appropriations are expendable only during the fiscal year for which they were appropriated. Provides that no budget shall become law without the Comptroller's independent certification that the planned expenditures are less than or equal to the revenue estimates for the ensuing fiscal year. Provides that appropriations for the current fiscal may not exceed the average annual revenue collected for the 3 prior years, adjusted in proportion to changes in population and inflation. Provides that within 30 days of the enactment of the State budget for a fiscal year, the Comptroller must certify whether the enacted budget will be balanced with expenses not exceeding funds estimated by the General Assembly to be available during that year. Provides that the Comptroller may find at any time during the fiscal year that the State budget has become unbalanced and so report to the General Assembly. Provides that a special session of the General Assembly shall be convened within 10 days of receiving a report from the Comptroller to enact a new State budget. Makes a conforming amendment to the Legislature Article. Effective upon being declared adopted.