Executioner's Greataxe (5e Equipment)
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Martial Melee Weapons
This oversized greataxe was intended for the chopping block, but those with excessive physique may utilize it as an functional weapon.
Execution. When you make an attack with this weapon against a target that is prone and you have advantage on the attack, you may use your bonus action to roll three dice for your attack roll instead of two, taking the highest value.
An executioner's greataxe carries social stigma. Most executioners try to remain anonymous because even in a society that agrees with execution there is mistrust of those willing to do the deed. It may attract unwanted attention. It may cause mistrust. It may cause someone who's had a loved wrong wrongly executed to blame the person who has the axe for the deed.
The weapon is difficult for most people to access. Most legitimate blacksmiths will only make such a weapon at the request of the government- and some might not even then. It might be a crime to make one outside of commission of the government. Having one may be a crime in some places if you are not actually an executioner.
It would be unlikely for an executioner's greataxe to 'go home' with the executioner. It would likely stay at some office of the law that retrieves it for duty.
The weapon should not be common for adventurer's to have. It isn't for them. Most characters who would dare carry this around are going to be evil and/or chaotic; not because the weapon itself is evil or chaotic but because it is unlikely a character without one or both alignments would be willing to reject society on such a scale. There are of course exceptions.
The most common time a character might interact with this weapon is when it is about to be used on official business. If someone is about to be executed and a fight breaks out the players may find themselves on the other end of the blade. However, as is the case many times when players end up on the wrong side of the law, a character may have to use this as a weapon as they or their friends escape execution. Either way, as a weapon that is not likely to be chosen as starting equipment this may prove to leave a big impact on the story.