Triumph was a prototype microprocessor-controlled board game invented by Alan Coleman and Roger Burten in 1979 that was, according to a successful lawsuit, an indirect ancestor of Dark Tower.
In February of 1980, Coleman and Burten demonstrated Triumph to a group of Milton Bradley executives, but Milton Bradley informed them that it was not interested in marketing their game. They were unable to find anyone else to market Triumph, and gave up on the project.
However, in 1981 the two inventors saw Milton Bradley's Dark Tower at the New York City toy fair, and concluded that MB had stolen their idea and used it to create Dark Tower. The pair sued Milton Bradley for misappropriating trade secrets, and MB was unable to demonstrate in the trial that anyone at the company had an idea for Dark Tower prior to the meeting with Burten and Coleman. A jury awarded them $737,058.10 for lost royalties. This award was initially set aside by the judge because of a technicality in the waiver Burten and Coleman had signed when submitting the game for consideration, but on appeal the award was reinstated.
This case appears to have become an important precedent in intellectual property law, and is frequently referenced in newer cases.
Unfortunately, not many details about the Triumph game itself are known. If you have information about Triumph, please contact me.
I have received an email in defense of Milton Bradley in this matter:
The Apple II game referred to was Synergistic Software's 1980 "Wilderness Campaign" by Robert C. Clardy, and it was remarkably similar to Dark Tower. You can watch a YouTube video of Wilderness Campaign gameplay by chaos5482 here.
For more information about Burten v. Milton Bradley, see Lee Gesmer's article here.