Matthew Hayward wrote: I'm curious how the DM determines what damage spot on the damage wheel to use.
Ah, here's one which I can answer as a trained combat DM!
I think there is a dot on the board somewhere and they see which pip is directed towards the dot?
Yes! It's often a red dot, with a small black circle around it. It's very small, so many people miss it.
And sometimes (very rarely) the board is missing the damage dot, and the DM has to mark one on with a pen.
Is the dot in the same spot on all boards?
No. It's usually on the right hand side of the board, kinda on level with the monster's head or torso, but the placement varies.
Are players supposed to know this / aim their puck based on the dot?
Yes, players are supposed to know it.
Usually the Training Room Coach does a run down of how combat works, and how damage is tallied, and should point out the little damage dot to all the players as part of the melee training. But sometimes it gets forgotten, and sometimes players say "We know how combat works" so the Coach just lets them practice, and other times the Coach is very clear about it, but people are excited and talking over each other, and it just doesn't register.
As for aiming...
It really depends on how you slide your puck. I know folks who are very good at lining up the high-damage side of their puck to land on the side of the board with the damage dot. Other people spin their tokens too much as they shoot. Still others find that trying to keep the damage dot lined up means they're not as accurate getting into the high ACs, so the dots are lined up nice, but they're outside the silhouette.
Use your training room practice time to see if your shots are predictable enough for you to "aim" your token. If so, you can try to make a habit of, say, keeping the high damage dots on the right as you slide. (Or on the top, if you routinely put a clockwise quarter twist on your token, etc.) If not - don't worry about it. Just slide; things tend to randomize over time. It's really not worth worrying about.
Note: You can be the most accurate slider, and have your damage lined up perfectly, and still get bumped by a team mate and find your token spinning 180, giving you minimal damage. C'est la vie.