Apple was dealt a major setback in its patent battle against Samsung today when a California judge ordered a new trial on 14 Samsung products and dropped more than $450 million in damages from the $1.05 billion the jury awarded to Apple last summer.

California district court Judge Lucy Koh found that the jury awarded damages “based on a legally impermissible theory,” so Samsung is entitled to a new trial on more than a dozen of its gadgets.

That includes the Galaxy Prevail, Gem, Indulge, Infuse 4G, AT&T Galaxy S II, Captivate, Continuum, Droid Charge, Epic 4G, Exhibit 4G, Galaxy Tab, Nexus S 4G, Replenish, and Transform.

“This amounts to $450,514,650 being struck from the jury’s award,” Judge Koh said.

However, Samsung is still on the hook for almost $600 million in damages related to the Galaxy Ace, Galaxy S (i9000), Galaxy S II i9100, Galaxy Tab 10.1 Wi-Fi, Galaxy Tab 10.1 4G LTE, Intercept, Fascinate, Galaxy S 4G, Galaxy S II Showcase, Mesmerize, Vibrant, Galaxy S II Skyrocket, Galaxy S II Epic 4G Touch, and the T-Mobile Galaxy S II.

“The total award for these 14 products is $598,908,892,” the judge said.

It appears that the jury relied too heavily on damages suggested by one of Apple’s expert witnesses. “Accordingly, the Court will consider which of these awards entailed the use of an impermissible legal theory, and what the appropriate response is,” Judge Koh wrote.

“We are pleased that the court decided to strike $450,514,650 from the jury’s award,” Samsung said in a statement. “Samsung intends to seek further review as to the remaining award. We are also pleased that the court earlier found that Samsung had not acted willfully, denied Apple’s request for a permanent injunction, and denied Apple’s motion for increased damages.”

The judge also considered a request from Apple for even more damages on five products, but she shot down that request. “There is a longstanding rule that the Seventh Amendment prohibits a judicial increase in a damages award made by a jury,” she concluded. “It is not the proper role of the Court to second-guess the jury’s factual determination as to the proper amount of compensation.”

Meanwhile, Samsung and Apple were at odds over damages for post-trial sales. Apple wanted the clock to start on July 1, Samsung wanted it to start after the conclusion of the trial. Judge Koh sided with Samsung and set it at Aug. 25.

Apple did not immediately respond to a request for comment.

Editor’s Note: This story was updated at 7 p.m. Eastern with comment from Samsung.