Specifically, I'm interested in what the laws about dueling were (if any) under Tsar Nicholas II? Was it legal or illegal? If illegal, were punishments enforced or was it sort of winked at?

Also, what would the preferred type of weapon have been? I assume, by this point, firearms would have been the instrument of choice but I'm curious what type of firearm would have been common.

Thanks for any help you can provide.