Reciting a scroll now takes some time. This time depends on how well you
know the spell(s) contained in the scroll. If you don't know the spell(s)
at all, you can still recite the scroll. Note that spell knowledge only
affects its reciting speed, not its strength (that is bound to the powerful
mage that inscribed the scroll ages ago). Like for normal casting, reciting
a scroll is longer if you are fighting.
Reciting a scroll can be interrupted (by the caster or on damage recieved),
the scroll is lost only when the spells in it are actually casted.