'Scare marks' in the title question because I realise that chivalry and codes of chivalric conduct are slightly dodgy terms. I'm writing my undergraduate thesis on chivalric literature, in particular, Sir Thomas Malory's Le Morte Darthur. When I think of a definition of chivalry, I tend to think of the Round Table oath that Malory writes - essentially (I'm paraphrasing from the 2004 Norton Critical Edition) not to assault or kill innocent people, not to commit treason against the King, not to duel other knights over property issues or over women, and to protect women (it specifically mentions that rape was punishable by death). Theoretically at least, knights were supposed to operate within these rules.
I've recently been thinking about how this pertains to earlier warrior cultures in different parts of Europe. I've read the Saga of the Jomsvikings, which mentions some rules about how this particular group of warriors had to behave. But, more generally, did Viking warriors adhere to any sort of system of good conduct, even if it wasn't as defined as chivalric values tend to be considered?
In Viking society as the previous poster described there were in fact laws and even lawyers, but perhaps a more chivalrous idea was the way they abhorred violence against women.
It was considered shameful to physically harm a woman in any way, in fact when raiding a house the women and children would be allowed to leave. These rules only applied to viking women however. Others would often be taken as slaves and treated as such during raids.
Sources will be found later since I'm on my phone currently.
Some quick research pulled up this source which backs up my previous comments. Haven't heard much about this source but they seem interesting I'll look into them a bit more myself.
http://www.hurstwic.org/history/articles/society/text/laws.htm - Viking Laws and Lawyers
http://www.hurstwic.org/history/articles/society/text/women.htm - Roles of Viking Women In Society
Honour and reputation was an important part of viking society. A "holmgång" (viking duel) to death was often held just over insults. Even so that in the icelandic law book "Grågåsen" stated that you were free to murder someone if they insulted you by saying you acted like a woman or "un-manly".
"Niding" was something you called someone that had lost their honour. Could be by attacking someone who could not defend themselves, refusing to participate in a "holmgång", breaking an oath or in some way acted like a coward.
There is a saying, still being used, "var mans niding" that means "every mans niding" or that you can defame a "niding" without any repercussions.
Another example is "varg i veum" with roughly means "a criminal in a sanctum" and were an other shunned or ostracized person in viking society. They were named that if they committed a crime or offence inside or near a holy place.
This may be more of a case of viking believing in luck but it was a disgrace to take the weapon of a fallen enemy. They believed that since the enemy was unlucky enough to die, his weapon has a part of that "un-luck".