Congress and the White House are playing high-stakes chicken, with a midnight deadline and the U.S. Government as the stakes.

Uncle Sam is due to run out of money tonight for most operations unless Congress passes, and the president signs into law, a new continuing resolution. Reagan has said he will veto the package if it exceeds spending guidelines he has laid down. A lot of people in Congress think he is bluffing. A lot of people in Washington suspect the crisis will fizzle after all the actors have had their say. Maybe so.

But if the crunch comes, this is a blueprint of what will happen in most federal offices beginning Monday:

* You will be expected to show up for work as usual on Monday, but the work you will be asked to perform will not be the usual thing.

* Except for those doing special jobs (outlined further down), workers cannot do anything or perform "services other than those involved in the orderly suspension of agency operations."

* Agency heads and managers will determine whether and when personnel "have completed all phasedown tasks incident to the orderly suspension of agency operations."

* Once that determination has been made, the Justice Department (based on a Nov. 17, 1981, ruling) says that: "At such time, the services of those employes can no longer be accepted in absence of appropriations."

* Personnel performing "excepted services" will be asked to keep working. The Justice ruling says: "All personnel performing excepted services, including activities incident to the orderly suspension of agency operations, should be assured that the United States will not contest its legal obligation to make payment for such services, even in the absence of appropriations."

* Excepted services, that is those that will continue even if agencies are technically out of money, include national security and the conduct of foreign relations "essential to the national security or the safety of life and property"; payments of benefits and contract obligations under "no-year or multiyear or other funds remaining available for those purposes;" conduct of essential activities to the extent that they protect life and property, including medical care of inpatients and emergency outpatient care, monitoring the safe use of food and drugs and hazardous materials, air traffic control and other transportation safety functions, border and coastal patrol and protection, care of prisoners, law enforcement and criminal investigations, emergency and disaster assistance, borrowing and tax collection on behalf of the government, maintenance of power distribution systems and protection of research property.

If you don't fall into one of those categories, and the budget crunch continues, many of you will be out of a job, at least temporarily, beginning as early as Tuesday.