Relative clause pronouns: was

Question

Confused by the use of was in the relative clause of the following sentence:

Zerfrisst die Rüstung des Ziels, was dessen Rüstungswert deutlich beeinträchtigt.

Erodes the armor of the target, significantly reducing its armor-value

or in an awkward, but more literal translation:

Erodes the armor of the target, whose armor-value becomes reduced.

I am assuming that the dessen here is a genitive-case article that corresponds to the modified noun Ziels. My question is: is the was here necessary? if so, why and how does it affect the meaning?

Answer 1

The literal translation is:

Erodes the armor of the target, which significantly reduces its armor value.

Was corresponds to which.

The literal translation of

Erodes the armor of the target, whose armor value is significantly reduced.

is

Zerfrisst die Rüstung des Ziels, dessen Rüstungswert deutlich beeinträchtigt wird.

The relative pronoun was in the German sentence refers to the eroding, not to the target as in your last translation. There is practically no difference in meaning but the original German sentence is a bit clearer about the reduction of the armor value being the effect of the eroding.

In the sentence above you can make it a bit clearer by adding dadurch (by it):

Zerfrisst die Rüstung des Ziels, dessen Rüstungswert dadurch deutlich beeinträchtigt wird.

Another option would be to use wodurch as a relative pronoun:

Zerfrisst die Rüstung des Ziels, wodurch dessen Rüstungswert deutlich beeinträchtigt wird.

which literally means:

Erodes the armor of the target, by which its armor value is significantly reduced.