More than a century after California gold miners started wearing them, and more than a decade after war protesters donned them as revolutionary garb, Levi's blue jeans are experiencing something they've never experienced before: a drop in price.

Suddenly, the world's most popular denim pants have become an outright steal, the result of daring price slashing by several national retail chains - nearly everywhere, it seems, but in Washington.

The price war, say Levi's non-H.D. Let, can't last. But for the moment, Macy's in New York, Rich's in Atlanta and The Gap in Minneapolis, among others, have marked $4 off Levi's bells and straight-legs which normally sell for $16 for $17 per pair.

In the Washington area, only a couple of stores have joined for bargain parade. Steven-Windsor's four suburban stores and Country Legend's Alexandria shop have been advertising the new low Levi's prices, and the District's General Store has been offering jeans at a discount for some time.

But the Levi's selection at all three is limited. Meantime, the largest local jean retailers - Giant's Pants Corral. The Gap and Woodward & Lothrop - are keeping their prices up, waiting for someone else among them to be the first to break.

"We think Levi's are a damn good value at the price they're at," said Robert Burke, executive vice president for general merchandising at Giant."They're selling well already. There's no sense upsetting a sales trend which is going well anyway."

Also, if Giant discounted now, Burke said he's afraid the chain's 26 jean outlets would sell out and have only empty shelves to greet back-to-school shoppers in the fall.

"The product is on allotment. If we sell out, we'll probably be unable to get more. If Levi's called and said they could supply us with as many jeans as we want, we'd drop the price tomorrow," Burke said.

The San Francisco-based Levi Strauss company - named after a Bavarian sailmaker who brought the dungaree to California gold miners in 1850 - has nearly 40 per cent of the national jean market. Demand for its pants has generally been strong, and the price war is making orders even harder to fill.

"The price war has stimulated our business rather significantly," said Robert T. Grohman, president of operations for Levi. "Stores are ordering and they're ordering aggressively."

Actually, the current price war seems to have been motivated less by worry over the future of the blue jean than by the aggressive bid of one company to increase its own market share. The retailer who started all the trouble was County Seat Stores, a 172-unit chain based in Minneapolis which last month began selling Levi denims and corduroys at $12.50 a pair.

Jack Crocker, president of Super Valu Stores which owns County Seat, said the reason for the price drop was "basic fundamental marketing" and is part of a strategy to claim a larger share of the leisure-wear market.