I couldn’t find it in the book but what do you roll when you bash someone with your shield? In Burning Wheel Gold on pg 555 it list the weapon stats for a shield, but I couldn’t find what skill to use for that.
Also, block says to test your weapon skill, but what if you have been disarmed or otherwise don’t have a weapon? Would you roll brawling/boxing? It doesn’t make sense to me to roll those if you are just blocking.
If I recall correctly, this came up in an old thread. Ah, found it:
Brawling it is. In general, shields are effective because of the fighting style used, which means what weapon it’s paired with, so you always use the skill of your weapon to hit with a shield. When you’re armed with a sword, that’s Sword, and when unarmed, that’s Brawling, whether blocking or bashing with the shield.
I can’t see using Boxing, since a shield would interfere with the form.
The shield training description (p295 BWG) includes “a suitable Boxing skill” in the list of skills that a character can use to shield bash.
A shield wouldn’t work with the forms of Queensbury rules sport boxing; especially if it were a targe or even kite shield. However, Royal Armouries Ms. I.33 (the earliest known European combat manual) mentions punching with bucklers as one of the fighting techniques, so it’s historically accurate.
As the Boxing skill has to be “suitable”, that suggests the boundary is based on what the group says is sensible; so, perhaps make the distinction between the fine accuracy of “Boxing” (Agility/Power root) and the more brutal force of Brawling (only Power root) by saying a small shield (i.e. +1D) can be used for shield punching with Boxing or Brawling but larger shields must use Brawling
I think you’re right about folding it into, or deciding it through, the fiction. I’d be tempted to go a similar way, by defining a Boxing style within the world that is compatible with small shields—anyone using Boxing with a shield has studied that style. That could be an interesting bit of colour too: “How does an Aturian know sess-ko boxing?! She must know someone from Deyarith… *dun dun DUN*”
If you were going for a more C16th fantasy world rather than Tolkienesque broadswords-and-armour, you could lean into if further, by having each several different Duelist LPs with a different set of Training Skills, &c.
As the scripting mechanics reward being able to predict your opponent’s choices, knowing what a fighting school trained in would give an advantage to someone who’d found out what their opponent’s school was in advance.