Talk:Marksmanship/@comment-99.199.125.202-20190420032830

Not sure about 'firebolt' but any spell with that has an 'impact' effect (i.e. knockdown, stagger, pushback, etc) such as Fireball (or Sunburst if you're a vampire) will break bows and crossbows.

Giant stomps / dragon landings (especially powered by DCO) and shouts do not break bows.

Dragon Breath attacks, however, DO break bows and crossbows - notably the 'projectile ball' type ice and lightning shouts. The 'channeled breath' type attacks do not affect them.