Why was triwizard tournament continued even when Dumbledore knew that it was dangerous for Harry?

Question

So the Triwizard tournament was a contest held between three wizards of different schools where they compete with eachother to get the cup. The tournament was held every 5 years, however it was discontinued after 1792. But later in 1994 it was resumed.

So this time Dumbledore had assured everybody that "no champion will find himself or herself in mortal danger." However later when he came to know that the fourth name that came from the Goblet of Fire was "Harry Potter", he was very tensed and even more anxious about third. Further not only Dumbledore, even Hagrid and other wizards were also worried regarding this event.

So my question is that why the tournament was not stopped even when the Goblet tossed the fourth name (which was a rule break)? And after this why Dumbledore was so anxious for Harry even after knowing that he was the "Boy who lived" or "The chosen one"?

Answer 1

The OP has asked two questions. While that’s usually discouraged, I’ll answer them both and migrate one of my answers if it gets split into it’s own thread.

Why was Dumbledore nervous when Harry’s name emerged from the Goblet?

Several reasons spring to mind:

• Harry's name was submitted in unusual circumstances.

  The Triwizard Tournament only has three champions, and now name number four comes out. Combine that with other suspicious events (the escape of Wormtail, the disappearance of Bertha Jorkins, and the Dark Mark at the World Cup) and he's going to be worried this is part of a larger plan. A plan which probably ends with Harry's death.

• Harry is a target.

  None of the other contestants have Death Eaters or dark wizards who'd like to kill them, only Harry. The fact that Harry was selected for a tournament in which people have died in the past, while there are people of people who'd like to kill him or see him die in an "accident" is bound to make Dumbledore nervous. The Tournament is designed to ensure nobody dies by accident, not from deliberate assassination attempts.

• Hogwarts has been infiltrated by somebody who means Harry harm.

  As Moody explains, deceiving the Goblet is a piece of magic well beyond a student. This didn't happen by accident; somebody specifically put Harry's name in the Goblet, and anybody with that level of skill is also smart enough to know that Harry would have to compete:

  “It’s very simple, Karkaroff. Someone put Potter’s name in that goblet knowing he’d have to compete if it came out.”

  and

  “It would have needed an exceptionally strong Confundus Charm to bamboozle that goblet into forgetting that only three schools and the three camps are to compete in the tournament.. . . I’m guessing they submitted Potter’s name under a fourth school, to make sure he was the only one in his category.. . .“

  That person would need direct access to the Goblet itself, which means they're able to get into Hogwarts. Concerns for Harry's safety aside, it's got to trouble Dumbledore that somebody this powerful and dangerous has broken into the school.

Lots of other people - including Hagrid, McGonagall and Snape - are smart enough to follow the same reasoning and realise that Harry's entry into the Tournament is suspicious, and cause for grave concern.

Why didn’t Dumbledore pull Harry out of the Tournament?

Again, there’s no single answer, but several reasons:

• There’s this “binding magical contract”.

  As Crouch explains, when several people suggest that Harry should be withdrawn:

  “We must follow the rules, and the rules state clearly that those people whose names come out of the Goblet of Fire are bound to compete in the tournament.”

  The only other magical contract I can think of is the Unforgivable Vow, the penalty for which is death. Although I doubt the Triwizard Tournament is quite that strict, Dumbledore may not want to let the penalty fall on Harry’s head, especially if it’s a severe one.

  (Perhaps you could argue that Harry isn’t bound by these terms, because he didn’t actually put his name in. Good luck trying to rules-lawyer an inanimate magical object.)

• It may put Harry in more danger.

  As stated above, Dumbledore knows that somebody dangerous is at Hogwarts, and their plan presumably involves Harry in the Games: it makes for an easy cover if he has an “accident”. If Harry’s not in the Games, then they’ll resort to other means. Whether that’s attacking him in the corridor, classroom or common room, Harry may be at more risk from a reckless attack, as might anybody else who’s standing near him.

  By contrast, the Games are strictly regulated and stringently monitored. If Dumbledore found evidence of foul play, then he could pull Harry out of a specific task. But pulling him out entirely means he‘ll probably be attacked in the halls, where there aren’t as many protections.

• It looks embarrassing for Hogwarts, and discredits Dumbledore.

  If Harry’s name comes out of the Goblet, and he’s immediately pulled out, then it looks like a publicity stunt. Dumbledore is already aware that plans are afoot (Jorkins, Dark Mark, etc.) and he’d probably prefer not to look stupid in front of the international community.

Answer 2

Dumbledore tells the Hogwarts students that once your name comes out of the Goblet, you're basically obliged to compete:

"Finally, I wish to impress upon any of you wishing to compete that this tournament is not to be entered into lightly. Once a champion has been selected by the Goblet of Fire, he or she is obliged to see the tournament through to the end. The placing of your name in the goblet constitutes a binding, magical contract. There can be no change of heart once you have become a champion. Please be very sure, therefore, that you are wholeheartedly prepared to play before you drop your name into the goblet." ("The Goblet of Fire")

Likewise, when Karkaroff threatens to pull Krum out of the tournament, Fake Moody basically tells him its impossible.

"Empty threat, Karkaroff," growled a voice from near the door. "You can't leave your champion now. He's got to compete. They've all got to compete. Binding magical contract, like Dumbledore said. Convenient, eh?" ("The Four Champions")

We never get a full explanation of exactly a "binding magical contract" works, or how Harry could be entered into one without his knowledge. But at the very least, three champions had voluntarily sworn to compete to compete in a Triwizard Tournament.

We're also never told what the punishment is for not fulfilling the contract. But we get two examples of "binding magically contracts in the books: The Dumbledore's Army list, which disfigures anyone who breaks their promise, and an Unbreakable Vow, which will kill you. Presumably, the effects of breaking a contract with the Goblet of Fire, a "very powerful magical object," is equally dire.

(It's also worth noting that Fake Moody's phrasing, namely that Karkaroff can't leave Krum, might imply that the headmasters are likewise bound to participate, in which case Dumbledore may have no choice.)

Answer 3

One simple reason, Once the Goblet of Fire chooses someone, you HAVE TO fight for the Triwizard Championship, there's no other way. You can't simply scrape one candidate because of safety issues, even if you are Albus Dumbledore...

Answer 4

Knowing who Dumbledore is and how he acts and (almost) kwows everything what is going on at Hogwarts he would have known (or had a good idea) what was up.

Maybe he reasoned that if someone now was going to harm Harry he or she would try it during one of the contests. Why would he enter Harry otherwise? And therefore was easier to protect him during 3 contests instead of having to do that 24/7. Dumbledore used Harry in more situations than this one to fight Voldemort or DE without Harry's full knowledge of the situation.

He, with others I suppose including the other professors, had control over those contests and would never let anything happen while still on school's ground. Dumbledore will count on the person who did this making a mistake of some sort wich would reveal his identity.

While doing this on "purpose", it's still a reason to be anxious because there's always the chance of something going wrong. Wich it nearly did.