THE PROBABILITY of a lame-duck session of Congress is rising - with interesting implications for the legislation on taxes and energy. There seems to be a spreading impression at the Capitol that, in particular, the entangled bill on natural-gas pricing might be easier to handle after the election. The Senate's majority leader, Rober C. Byrd of West Virginia, offered the opinion a few days ago that if there's no energy bill by the election, and if there's "any reasonable hope" for it, Congress ought to come back in November to finish the job.

There's been speculation for some time that the tax bill might be headed for a special session after the election. President Carter is threatening to veto the bill that the House has passed. But now it goes to the fertile imagination and craftsmanlike skill with which it fashions special breaks for special interests. The talk of a veto can become self-fulfilling. In the sweaty days of late summer, especially next month as the campaigns get under way, there's always a certain temptation to load up a bill with outrages. Why not, if the certainty of a veto rescues everyone from the necessity of having to live with the resulting legislation?

One scenario suggests passage of a vandalized tax bill in October, followed by a veto and - after a brief pause for the election - a short session in which to enact a more respectable version. It may come to that, but that, but the strategy is dangerous. The extremely short time available, and the great complexity of the subject, put great influence in the hands of a few key people - one of whom is Sen Russell Long (D-La.), whose chairmanship of the Finance Committee has contributed so much to its special character and reputation. The session would become even more complicated if Congress were trying, in those few weeks before Christmas, to finish both tax and energy bills simultaneously.

The peculiarity of a lame-duck session is owed to the number of votes cast by members who will not be returning. This year that number would probably be unusually large. Ten senators and 49 representatives, an unprecedentedly high total, have decided not to run for re-election. No doubt there will be others in November whose retirement is less voluntary.

There have been five lame-duck sessions since World War II. One of them in 1950 was during the Korean War, when Congress stayed in town nearly continuously. One, in 1954, undertook in the post-election calm the delicate business of censuring Sen. Joseph McCarthy. One, in 1974, followed the Nixon resignation and the onset of a dangerous recession; Congress returned to enact emergency economic legislation. Two of these sessions, in 1948 and 1970, resulted from the antagonisms between a president of one party and a Congress of the other. Oddly, it is those last two cases that the present situation most resembles. The president and the congressional majorities are all Democrats, but they are pointed in very different directions on the central questions of this administration.

In terms of political perceptions, a session after the election might be expected mainly to benefit the president. It would suggest vigor and steadfast determination in pressing his purposes. In Congress, the prospect of an extra session would make delay a less formidable tactic than usual in an election year. It's probably fair to say that a lame-duck session is not, at this point, anybody's first choice. But the possible advantages, both to the White House and to the congressional leadership, and becoming more compelling.