What were medieval, Viking-Era, Scandinavian laws regarding rape?

Most countries' laws distinguished between "citizens" and "others," such as foreigners, or domestically held slaves. So what the Vikings considered "legal" when perpetrated against foreigners abroad would (probably) not be a "reasonable approximation" of what was acceptable at home. If anything, their "progressivity" at home would probably give "citizen" women strong rights against male citizens. Even today, I know "Viking" (Swedish and Danish) men who prefer to date foreign women because "their own" are relatively inaccessible to them. This may have been true in medieval times as well.

"Universal," or global laws are a relatively recent phenomenon. For instance, the Geneva (and similar) conventions regarding captured prisoners of war and conquered civilians were signed only in the late 19th and early 20th centuries. The most relevant universal legislation is German statutory rape laws; a German citizen can be arrested anywhere in the world for sleeping with a woman under the age of 16 (the German age of consent), even in Thailand or other Asian countries, where the age of consent is lower. Medieval Vikings would not have had such laws regulating "foreign" rape.

As far as I'm aware, the law codes of Norse communities in the Viking-Age weren't written down, but were rather memorised by "law-givers". These gradually became more-or-less standardised by the end of the period when they were written down by Christian monks.

As a result, we have to rely on the sagas. The 2015 thesis, Justice Done: Outlawry Crimes in Medieval Iceland by Sarah Stapleton may give some guidance. It appears that even kissing a woman without her consent could be punishable by outlawry. Since outlaws could be killed with impunity, this might have amounted to a death sentence.

On page 25 of her thesis Stapleton also observes:

There is also a law against wrongful intercourse, which states that a male principle in a case may kill another man if “a man arrives to find another man forcing a woman to lie with him there...,” or if “... the man has forced her down and lowered himself down upon her.

She quotes her source here as:

Dennis, Andrew, Peter Foote, and Richard Perkins, trans., Vol. III of Laws of Early Iceland: Grágás I, the Codex Regius of Grágás, with Material from Other Manuscripts. Edited by Haraldur Bessason and Robert J. Glendinning. Winnipeg: University of Manitoba Press, 2006, p154

My thesis is the one sempaiscuba♦ suggested. Your question is far more complex than one might think on first glance. In the short, it varies from place to place and it depends on where the crime was committed.

First, one must understand that the raping and pillaging actions of the Vikings were commonplace in most areas and of most people in Europe, especially during wartime, but the Vikings became particularly noticeable because they were not Christians and Christians provide most of the non-Viking sources of Viking behavior. It is like the enemy writing the history of a defeated foe, while conveniently disregarding their own actions.

Second, one must understand that raiding was part of Viking culture which developed out of scarce resources. Lack of primary sector industrial goods, such as ores, wood, and food stuff made pillaging a good way to get necessary goods and create wealth.

Within the context of this understanding, sexual misconduct in any fashion within Iceland had direct repercussions to the instigator, and occasionally the victim, by means of outlawry. Outside Iceland, the laws of those lands dictated the repercussions, though it is widely believed that Icelandic law was a modified version of Norwegian law so anywhere that spoke Norse had some basis in those laws. For example, in the English Danelaw, it is likely the people living there were subject to laws similar to Icelandic lawsbecause they were developed out of Norwegian ones, with a bit of Anglo-Saxon law to keep the peace with the Anglo-Saxon rulers of the what is today southern England. The same is likely true of the Shetlands and much of Scotland.

Normandy was subject to French authority so it would have followed French law, but only if the perpetrator was caught. Oftentimes, they were not due to their ability to raid quickly and move on before reinforcements could arrive. Beyond that, the Vikings traveled all over Europe and it is difficult to say with any certainty what the laws in those places where because there are few, if any, written sources. This is especially true of eastern Europe.

I hope this helps!