I already did quote example about English law, but here is other example from the same Wikipedia page.
"However, even allowing for mistakes made in a crisis, the amount of force must be proportionate and reasonable given the value of the interests being protected and the harm likely to be caused by use of force. The classic test comes from the Australian case of Palmer v The Queen, on appeal to the Privy Council in 1971:
"The defence of self-defence is one which can be and will be readily understood by any jury. It is a straightforward conception. It involves no abstruse legal thought. ...Only common sense is needed for its understanding. It is both good law and good sense that a man who is attacked may defend himself. It is both good law and good sense that he may do, but may only do, what is reasonably necessary. But everything will depend upon the particular facts and circumstances. ...It may in some cases be only sensible and clearly possible to take some simple avoiding action. Some attacks may be serious and dangerous. Others may not be. If there is some relatively minor attack it would not be common sense to permit some action of retaliation which was wholly out of proportion to the necessities of the situation. If an attack is serious so that it puts someone in immediate peril then immediate defensive action may be necessary. If the moment is one of crisis for someone in imminent danger he may have [to] avert the danger by some instant reaction. If the attack is all over and no sort of peril remains then the employment of force may be by way of revenge or punishment or by way of paying off an old score or may be pure aggression. There may no longer be any link with a necessity of defence... If a jury thought that in a moment of unexpected anguish a person attacked had only done what he honestly and instinctively thought was necessary that would be most potent evidence that only reasonable defensive action had been taken."[2]
In R v Lindsay,[3] the defendant, who picked up a sword in self-defence when attacked in his home by three masked intruders armed with loaded handguns, killed one of them by slashing him repeatedly. The prosecution case was that, although he had initially acted in self-defence, he had then lost his self-control and demonstrated a clear intent to kill the armed intruder. The Court of Appeal confirmed an eight-year term of imprisonment. It would not be expected that an ordinary householder who "went too far" when defending against armed intruders would receive such a long sentence."
http://en.wikipedia.org/wiki/Self-de...in_English_law
"One recent case on using force against a burglar is Anthony Martin v R (2001) EWCA 2245,[2] which resulted in the householder being convicted. As the law currently stands, a person in possession can use no more force than they reasonably believe necessary to remove a trespasser from the premises. Further, where the threat to the land or its possession is not immediate, and other measures could be taken that would make force unnecessary (e.g., calling the police or seeking remedies through the courts) the defence will normally be lost."
http://en.wikipedia.org/wiki/Defence_of_property