Alter Aeon Online Help

Keywords are:  'druid spell thorn armor thorns'

Spell: thorn armor              Mana:  35  Int: 28  Wis: 30  Lvl 30 Drui  (28%)
                                (critical)   Requires: entangling roots
                                Group: Druid plant lore
                                Damage Type: stab (special, see text)

Usage:
cast thorn armor

The 'thorn armor' spell forces magical thorn vines to grow from nothing
to cover you in a protective layer.  The vines move seamlessly with you
as you move, both protecting you and keeping the thorns from injuring
you.

While the magic of the spell keeps you from hurting yourself on the thorns,
that same magic attempts to needle any attackers which get too close.