Maryland's 77-48 basketball victory over William and Mary last night was a welcome yawner for the Terrapins, the boredom of which was relieved chiefly by the remarkable antics of freshman John Johnson and the stomping of feet calling in vain for Len Bias to come back to the Cole Field House floor.

Johnson's jumper with 1:43 remaining and the accompanying free throw on the foul he drew gave Maryland its biggest lead of the night, 74-44. The 6-foot-4 freshman guard from Knoxville, Tenn., has looked more like a find with every game this season, and this was his first in double figures. He had 15 points that came from an entertaining variety of shots.

Johnson's last basket, to provide the 30-point lead, came long after Bias had left midway through the second half with a game-high 20 points in 29 minutes. The all-America forward has had 20 or more points now in each of Maryland's five games (4-1), and Maryland fans wanted more. But Coach Charles G. Driesell, with the game in hand, decided Bias had left for good with his third foul at 11:58.

William and Mary had only one player in double figures: 6-9 junior center Bob Dail with 17 points. The next closest was forward Mark Batzel with six.

The Indians were plagued by inexperience and turnovers, 13 in the first half against a trapping Maryland defense, and 19 for the game. They trailed by 38-17 at the half and never could come closer than 21 in the second period.

However, Maryland's victory over a team that had just one returnee with any experience had little significance other than as a warmup for Nevada-Las Vegas, which comes to Cole Field House to play at 8 p.m. Saturday. The Rebels are a strong, physical team anchored by 6-9, 230-pound forward Armon Gilliam. The last time the Terrapins faced that sort of opposition they lost, 78-66, at Ohio State.

"It was a win," Driesell said. "I hope it was a good tuneup for Las Vegas, because they're going to be a lot tougher."

Maryland was outrebounded, 40-28, against Ohio State, and to avoid a repeat against UNLV the Terrapins will once again go with what they call their "big" lineup, which against weaker opponents so far has seemed a grand success. Reserve 6-6 forward Speedy Jones has been moved to shooting guard with Keith Gatlin at the point. Against William and Mary, Jones had eight points and four rebounds.

"Speedy played okay, but I'll be more concerned with what he does Saturday night," Driesell said.

Most of the Indians' trouble came from their loss of composure against an impressive Maryland trap that was being polished for UNLV. The Indians (1-3), who lost four starters to graduation, had just seven points in the final 10:54 of the first period after playing ball control and holding the score to 10-10 in the first nine minutes.

Maryland then went on a 28-7 streak, holding them scoreless in stretches of three and four minutes.

"We played 10 very good minutes and then 10 very poor minutes to go down at the half," Indians Coach Barry Parkhill said. "The main thing was the inexperience against the trap; they'd never been in that position before."

The final five points of the half came from Johnson, two jumpers and a free throw. His performance was good news for Maryland's bench, which consists of only one veteran in guard Jeff Baxter, and then three freshmen, Johnson and centers David Gregg and Tony Massenburg. In addition to his 15 points, Johnson had three assists and no turnovers in 23 minutes.

"He played like a sophomore or junior," Bias said.

Maryland won't see much slowdown against UNLV (4-1), and the trap may not be quite as effective against a more experienced Rebels back court that includes junior point guard Fred Banks, averaging 18.2 points to go along with Gilliam's 14.6, and 16.2 from 6-6 guard-forward Anthony Jones, formerly of Dunbar High and Georgetown.

"They'll play us the exact opposite of William and Mary," Driesell said. "They'll be fast-breaking and pressing, and they won't throw more than a couple of passes before they shoot."