What happens when a Triwizard Contestant refuses to participate?

Question

It seems different enchantments trigger different consequences - for example, Lily's protective enchantment over Harry disappears the moment Harry turns seventeen, and the Unbreakable Vow results in death if broken. What constitutes the 'binding magical contract' in Goblet of Fire regarding the Triwizard Tournament? What are the repercussions of breaking the Triwizard contract? Both Dumbledore and Mad-Eye Moody stress the fact that Triwizard champions cannot withdraw from the tournament. However, I cannot find any canon reference to what would happen if a Triwizard champion outright refused to participate. Is there any canon source that addresses this? Please no Wikipedia/Wikia answers - I'm looking from information from the books or J.K. Rowling. An appropriate speculative answer based within the spirit of canon if a canon reference cannot be found is fine. For reference:

‘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 champion.’ - Dumbledore -

_{Goblet of Fire - page 226 - Bloomsbury - chapter 16, The Goblet of Fire}

and

‘He’s got to compete. They’ve all got to compete. Binding magical contract, like Dumbledore said. Convenient, eh?’ - Mad-Eye Moody -

_{Goblet of Fire - page 244 - Bloomsbury - chapter 17, The Four Champions}

Answer 1

A magical contract would be able to cause its effects through two systems that I can think of:

• Compulsion, to cause the party to want to comply with the contract.
• Enforcement, by providing a negative action on those who do not comply with the contract.

Extrapolating based on what little canon we know, the contract obviously does not force the contractee into taking part by compulsion as Harry is repeatedly unwilling and reluctant to take part, only to be effectively ordered to do so by the organizers.

That leans me to believe that in this case, enforcement is how a magical contract goes about its work - especially since the most closely corresponding magic to what we know of the magical contract is the Unbreakable Vow, which also does its work via enforcement, and we do know what happens when you break the Unbreakable Vow:

"Well, you can’t break an Unbreakable Vow...."

"I’d worked that much out for myself, funnily enough. What happens if you break it, then?"

"You die," said Ron simply. "Fred and George tried to get me to make one when I was about five. I nearly did too, I was holding hands with Fred and everything when Dad found us. He went mental," said Ron, with a reminiscent gleam in his eyes. "Only time I’ve ever seen Dad as angry as Mum, Fred reckons his left buttock has never been the same since." (Harry Potter and the Half-Blood Prince)

Harry taking part in the Tri-Wizard tournament is viewed as a potential death sentence:

"Don't you?" said Moody quietly. "It's very simple, Karkaroff. Someone put Potter's name in that goblet knowing he'd have to compete if it came out."

...

"Maybe someone's hoping Potter is going to die for it," said Moody, with the merest trace of a growl. (Harry Potter and the Goblet of Fire)

It'd take some serious enforcement to make it worth risking potential death for. Given the analogous Unbreakable Vow and making Dumbledore and the likes willing to risk Harry's life in the Tournament, I can only come to the conclusion that the effect of breaking the magical contract is indeed death or some lasting injury, mental or physical. Nothing else seems to make sense given the evidence. And with those risks in mind, I can see the teachers not wanting to inform Harry of these risks in order to avoid distressing him any further than necessary.

Answer 2

Harry has to compete because if he doesn't, he'll die (probably).

In what can only be described as the stupidest plot-twist ever, it turns out that in a competition designed to be entered by children, the Goblet is set to mete out a severe punishment to anyone who refuses to take part.

My reading was that since competing in the competition (the first task of which involves facing a giant man-eating dragon) is the lesser danger, this punishment must be either deadly or mind-destroying:

‘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 champion. Please be very sure, therefore, that you are whole-heartedly prepared to play, before you drop your name into the Goblet

It appears that the three heads lack the ability to change or cancel the results, even if the Goblet throws a wobbly:

Bagman wiped his round, boyish face with his handkerchief and looked at Mr Crouch, who was standing outside the circle of the firelight, his face half hidden in shadow. He looked slightly eerie, the half darkness making him look much older, giving him an almost skull-like appearance. When he spoke, however, it was in his usual curt voice. ‘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.’

and

‘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?’

and

Don’t you?’ said Moody quietly. ‘It’s very simple, Karkaroff. Someone put Potter’s name in that Goblet knowing he’d have to compete if it came out.’

Answer 3

I'm reasonably sure there is no canon answer.

The answer to this question probably relates to several factors. Depending on how one interprets those factors, one could arrive at several different answers.

1. Binding magical contracts would either provide for:

   a. Punishment of violators and/or

   b. "Encouragement" to fulfill the contract

2. The Triwizard Tournament has a history of being dangerous (thus limited to "of age" students)

3. The tournament does not have a previous history of being limited to "of age" students

4. The tournament has been around for a while

   This is relevant because in times previous, there was much less consideration of safety - particularly where children are considered

I think that the consequences would be very unpleasant and would increase in severity if the contestant continued to refuse. The first time would probably be something visible that didn't interfere with their ability to compete: hair loss, hair turning color, skin turning color, etc. The second time would be painful and/or debilitating. The third time would be fatal.

Answer 4

There's no way to know for sure, though we can compare the situation to the Unbreakable Vow. (emphasis mine).

“An Unbreakable Vow?” said Ron, looking stunned. “Nah, he can’t have. . . . Are you sure?” “Yes, I’m sure,” said Harry. “Why, what does it mean?” “Well, you can’t break an Unbreakable Vow. . . .” “I’d worked that much out for myself, funnily enough. What happens if you break it, then?” “You die,” said Ron simply.

Though different, both the act of entering your name in the goblet and the act of making an Unbreakable Vow seem to be ways of signing magical, binding contracts. In both cases, it seems the person has absolutely no choice but to comply with their end of the contract, whatever it may be. It is impossible to know what would happen if Harry refused to participate, but since the tournament means a high risk of death, not participating most likely means certain death.