User blog comment:G0LD3NF1RE/The Elder Scrolls at E3 2012/@comment-3428817-20120607092634/@comment-4588723-20120609183147

Definitely becoming obsessive here...the archery tree will apply to crossbows just like the Block tree applies to two-handed weapons; most block perks aren't exclusive to shield users, and aid those who block with their 2-hand weapons (this wiki's pages provide good info on both skills). Likewise, regardless of how you use your crossbows at SCA reinactments, the listed perks are just as useful in-game: damage increase = damage increase regardless of what you call it, the ammo perk will let you retrieve more projectiles from your victims, whether arrows or bolts doesn't matter, and the mechanic for aiming by using the block key should still work regardless of the weapon, so the only archery perk that probably won't translate is moving faster with a notched projectile, since as Ryker mentioned you're not drawing anything back to fire. On the upside, they might surprise us with one or two crossbow-specific perks grafted into the archery tree....we should make suggestions to Bethblog...