If General Chang was opposed to Gorkon's plans for peace with the Federation, why did he not openly challenge Gorkon in combat?
Because Klingons don't all act exactly alike just because they have a putative code of behavior. Chang was devious and manipulative. I'm sure he paid lip service to the rhetoric about honorable open combat and whatnot, but he preferred more secretive tactics. Besides, there's more to government and politics than winning a fight. It's not pro wrestling. Killing the seated chancellor won't do you much good if you don't have the support of the rest of the council, or at least a large enough fraction of it to overwhelm the chancellor's loyalists. Chang was a shrewd politician, so maybe he recognized that the Council was too loyal to Gorkon, that there weren't enough people backing Chang to let him solidify a claim to the chancellorship even if he did kill Gorkon. In that case, someone else would've probably challenged and killed Chang immediately thereafter. So instead he chose to act more deviously -- to kill Gorkon and pin it on Starfleet, so that even if Gorkon's coalition in the Council put one of their own in the chancellorship, they would still define the Federation as their enemies, as Chang wished.
^Exactly. I'd add that Chang's motivation wasn't so much to gain power for himself as it was to maintain the status quo in the Alpha Quadrant. Gorkon was willing to work toward peace with the Federation and presumably had the Council's support in order for the process to move forward. Had Chang killed him in honorable combat, his death may have actually had the opposite effect that Chang intended: a martyred Gorkon may have gained even more support for his cause than he would have otherwise had. Chang needed to be sure that the Federation was held responsible for Gorkon's death so that both sides would start preparing for all-out war rather than sitting down at the negotiating table. --Sran
Chang's real goal was war with the Federation, and framing Starfleet for Gorkon's death aided that agenda.
Sounds like you're applying the qualities and values of the Rick Berman-era Trek spinoff honorable warrior Klingons to Nick Meyer's militaristic movie Klingons.
Chang was a thug with no honor and instead of challenging Gorkon openly he became part of a subversive plot to assassinate him.
Klingons can only challenge under certain conditions for things like dereliction of duty, dishonourable conduct or cowardice. In DS9 Worf challenged Gowron because he dishonoured himself by squandering ships and soldiers in battles they couldn't win after becoming jealous of General Martok.
Indeed, Klingons are not above sneakiness. Remember them poisoning the grain in "Tribbles"? The stated ideals of any culture are just that: ideals. Doesn't mean that everybody is going to live up to them all the time.
Also, covertly arming the natives on Tyree's Planet, and subverting diplomatic relations between the Federation and Capella IV. Greg's correct -- not every confrontation in Kirk's era started with engaging a D-7 battlecruiser.
There's also Duras employing assassins to kill Kurn and Picard, rather than taking them on openly himself. Then there's his poisoning of K'm'pec.
As others have already mentioned. Chang might not have enough support on the council to hold onto his claim. It's one thing to become chancellor it's another thing to lead the council. A Klingon killing Gorkon who didn't have the backing of the Majority might make Gorkon a martyer to the cause of peace. Chang might not even have had the support of the majority of the military. So as others have said he had to esnure the Federation was held responsible for Gorkon's death.
Is there a line of succession thing in Klingon culture? Chang was the war guy, but maybe he was still a rung or two below Gorkon, and would have had to challenge a few other council members to get into a position where he was Gorkon's immediate subordinate, and could therefore legally challenge him? Azetbur is another question. Given that TNG established females being unable to rule the High Council, I always reasoned that Gorkon's death created something of a constitutional crisis, which is why Azetbur was able to step in as a kind of 'caretaker Chancellor'. I do recall that the TUC novelization posits the theory that Gorkon had put a line-of-succession to her in place just in case something did happen to him.
^One of the Lost Era novels posited, IIRC, that the "no women on the Council" rule was created after Azetbur's death as a move by her political enemies to make sure no more women got to be Chancellor.
The game Klingon Academy explained this, Chang owes Gorkon a blood debt so he couldn't outright challenge him, leading to his evil sneaky plan. Call it canon or not, it had the actors
I've heard a lot about that game and saw a few clips on youtube of the actors parts. Is it a good game?
It's a great game. With a wonderful story and it still looks good after so many years. Too bad I can't play it on Windows 7