Is the trigger for being able to get this having 1 or more copy of Crushing Punch in your deck/library? It seems like that would make a kind of sense. If only we knew how to get Crushing Punch.
I'm pretty sure that the way to get this skill is to either kill a certain number of enemies while using a melee deck, or to use a certain number of melee techniques in combat. I also think that only the fights you've had after you've trained once with the bum count, but I'm not entirely sure about that.
My working theory on this one had been having thrown at least X punches in melee combat. Argeth suggests that the trigger may be knowing at least X basic melee techniques. If this is right, the ones the Friendly Bum teaches (Punch, Lash Out, and Jab) definitely count. Crushing Punch almost certainly counts. Not sure about Brutality, Cruel Slash, Ghoul Bite and the like. If Argeth is right, it at least means getting extra instances of Punch isn't entirely worthless.
90% sure that you need at least 10 melee power before you can get pugilism, possibly with other requirements as well.
No, that's not right, Al from last year. I've got clear documentation saying otherwise. Also Mal from the past year, I'm just about certain that Brutality, Cruel Slash, Ghoul Bite almost certainly do not count to whatever counter triggers acquiring pugilism
Okay, time to let out one of my speed running secrets as I am apparently the only person to go the melee route when speed running. In the beginning of this year, when I would use the Cinematic Dodge -> Dive for Cover -> Punch -> Lash Out/Brutality chain, I would always get the pugilism skill after reaching the point of my run where I kill the 2 writhing masses to unlock Experimental Chemistry. Just to be clear, I trained with the Friendly Bum a total of 2 times in the process of getting this skill in those runs.
This new season though, where the Prototype Coat does not exist, I was using the Dive for Cover -> Shield Block -> Brutality/Cruel Slash/Lash Out -> Ghoul Bite chain. I only had 2 instances of Lash Out in my melee deck. I went through just about the entire run before attempting to get pugilism. I failed to get it despite the much extra fighting I did in the Damaged Building.
So, almost certainly using Punch, Lash Out, and Jab a certain number of times unlocks acquiring this skill.
Coming off of a Firestarter run where I used only fire and evasion, I switched over to a deck with Ragged Dodge, Leaping Dodge, and Dive for Cover for evasion, and for melee Swordplay, Clashing Blow (after I learned it), Punch, and Brutality, i.e. no Lash Out or Jab. I have yet to learn any instances of Crushing Punch. After using Punch 55 times in various fights, I learned the skill when I talked to the GG again. That was 55 punches thrown, total, often several in one fight. I did not think to keep track of unique fights in which I used at least one instance of Punch until it was too late.
My gut feeling on this is that the unlock for the skill is throwing 50 total punches after first training with the GG, but obviously we'd need more data to nail it down.
I finished an Etheric Master run, where again I had not used Punch at all the whole run. I talked to the Golden Glove, then used Punch 48 times in combat and talked to him again. No skill. I used it twice more to make an even 50, talked to him again, and go the skill. 8 of those fights were losses, so I don't think it matters whether or not you win as long as you use the technique.
EDIT: Still to spade: