I was watching some Nichijou, and in this one scene where Mai and Yuuko are helping Mio with her manga, Mai wrote in one of the text bubbles, "はっとばすぞ" and on the screen it translates to "Don't make me hit you." I feel like this is wrong, since there's no mention of "打{う}つ" (to hit) and it's too short to translate to that. So I was wondering, does this translate to that at all or is the translation really crappy?
Also how does "はっか場すぞ" translate as "Don't make me kill you"?
Actually, that is not a crappy translation at all.
Literally, 「はっとばすぞ」 means "I'll knock you flying!", so "Don't make me hit you." , while grammatically very different, carries a similar meaning.
The dictionary form of 「はっとばす」 is 「張{は}り飛{と}ばす」. 「ぶっ飛{と}ばす」 also has a very similar meaning.
"Don't make me kill you!" is also not bad at all as, I hope, you now could see.
Translations do not always need to be produced word-for-word as long as the intended meaning of the original is maintained, which is the case here.
You might want to read the following Q & A.
はっとばす is simply a sound change of 張り飛ばす, so はっとばすぞ by itself just means "I'll slap you." 張る can mean "to slap." See the 5th definition here.
But note that it's only the latter half of the sentence. The whole sentence is 「あんまじゃじゃ馬してっと、はっとばすぞ」. あんま is short for あんまり ("too much"). じゃじゃ馬する here is something like "to be naughty", "to act as one pleases", "to be at the whim", etc. してっと is colloquialism for していると. So the whole sentence is "If you keep acting naughtily too much, I'll (have to) slap you."
The implication of the whole sentence is simply "Be a good boy", after all. Someone euphemistically translated this into English as "Don't make me hit you", but I hope now you understand why.
はっか場すぞ is a pun on 墓場【はかば】 (graveyard), and it's extremely difficult to translate into English. The literal translation ("If you keep acting naughtily too much, I'll graveyard you") certainly will not work as a joke, but I don't know if "Don't make me kill you" works, either...
