...Everything's fair game in a battle of wits; and...
...Guns are the supreme equalizer in a battle of physical strength (if it should come to that)
Yes and no. There's a limit to how far people should go, if devolution is to the degree of deliberate malice or harmful behaviour. Say it was known that someone has a personality disorder. How far will their opponent go to poke at their known weaknesses?
A battle of wits can be a blast! As long as it's kept within boundaries of reasonably respectful behaviour or non-malicious humour and at the end, shake hands and wander off.