何故もっと早く来ないんだ。質より量を......数に任せて、非力な魔法使いを捕えておかないんだ。
So this is from an RPG. You go in a dungeon and find the 魔法使い (who was captured by the bandits). Then the bandits appear. Then the main character says this line to the bandits.
何故もっと早く来ないんだ。質より量を......数に任せて、非力な魔法使いを捕えておかないんだ。
So this is from an RPG. You go in a dungeon and find the 魔法使い (who was captured by the bandits). Then the bandits appear. Then the main character says this line to the bandits.
(Explaining form:)
I am going to translate the whole quote, using capitalizations and variant spellings to show where the Japanese grammar here induces emphasis:
(End explaining form.)
Ye'r SLOW! POINTS! Fergit doin' it right, GET MORE POINTS! And what are you doing trying to take this WIZARD WHO HAS NO POWER!
Roughly translated.
(Explaining explanation:)
The script of many RPG adventures is designed to engage and challenge the player. One stock form of challenge is the insult from the hidden guru.
(End explaining explanation.)
You have been insulted three ways.
「捕まえておく」 would mean, roughly, "capture/take and be done with it." In the related questions @naruto suggests, this form is derived from a phrase indicating making preparations by doing something, in this case, taking a wizard.
「〜捕まえて置かないのである。」 would mean, "It is not to be done, to capture ..."
Oh, there's another thing going on to confuse things, 「〜のである」 changing to 「〜んだ」。
(Comment on grammar:)
Consider the difference between the following two:
(1R) 「赤い。」 (Something is red.)
(2R) 「赤いのです。」 (There is a state or fact of redness.)
In the second case, the fact is being presented as a fact, and is likely being presented as a reason or something like a reason.
Now consider the difference between
(1T) 「飛ぶ。」 (Something flies.)
(2T) 「飛ぶのです。」 (Now there is a fact of a state of flying.)
(3T) 「飛ぶんだ。」 (The fact of the state of flying has been emphasized.)
The form in (2T) could be used as an explanation of something, but is more likely to be a substitute for the command form, which could be interpreted as "You will fly."
The form in (3T) is a relaxed form of (2T). I don't mean relaxed as in how you feel when visiting the [温泉]{おんせん}, I mean, as in 「[砕けた]{くだけた}[表現]{ひょうげん}」. The rules have been relaxed because of some necessity or privilege. There is a definite sense of the assertion of authority, emergency, or force.
Here, there is no true emergency, nor any real authority or real force, so I translated it as emphatically spoken in a rough dialect.
As far as I know, the choice of where to insert the emphasis is somewhat arbitrary. I could have written, for instance
... trying to TAKE THIS wizard who has no power!
among other possibilities.
Oh, and I am taking a bit of interpreter's license in choosing to interpolate rather than use the more direct translation of
You shouldn't be capturing this weakling wizard!
(End comment on grammar.)
(One more afterthought:)
It almost goes without saying, but I guess I'd better say it (thanks, Chocolate.) --
The whole quote could be interpreted as a negative imperative query, inverting the last part:
Why did you take so long, and [why don't you] go for points instead of skill and take this weak wizard?
Don't think too deeply about this or you won't have fun playing the game.
(End one more afterthought.)