1.0 link Rainbow Dash Network http://rainbowdash.net/ Cerulean Lulamoon-Spark (ceruleansparkold) http://rainbowdash.net/ceruleansparkold http://rainbowdash.net/notice/372490 @<span class="vcard"><a href="http://rainbowdash.net/user/2171" class="url"><span class="fn nickname">sparklepeep</span></a></span> My personal explanation of Unicorn magic is that everypony has magic, but can't project it outside of themselves, unassisted. Pegasi use it for their oddly inertialess flight and gravity-defying hovering. Earth ponies use it for their legendary endurance and strength. Pinkie uses it to...be Pinkie Pie. For Unicorns, the horn is essentially a conductor, so blocking magic at the neck would stop them from casting because the horn wouldn't have access to any reserves....but that doesn't have anything to do with the story, which I admittedly haven't actually read.