Total cover prevents any attack against you. You can
use a tower shield to get total cover if you give up all your
attacks. What does “give up all your attacks” mean? Can
you move while getting total cover from the shield? Can
you cast a spell? Also, do you get total cover from all
directions or from just one side of your square? Will the
total cover from a tower shield negate spell effects? Will it
negate attacks of opportunity from movement or from
other actions such as spellcasting? Will it prevent charge
attacks against you? What about bull rush attacks? Can it
prevent grapple attacks or snatch attacks? Will it stop fear
effects, gaze attacks, or clouds of poison gas? Will it defeat
traps?
To claim total cover from a tower shield, you must use a
standard action. The tower shield rules don’t say that, but that’s
what they mean. Since you can take only one standard action
each round, you cannot also attack, cast a spell, activate a
magic item (except for some use-activated items), use a special
ability, use total defense, or start or complete a full-round
action during the same round you claim total cover from the
shield. You can, however, take a move action before or after
you claim cover from the shield.
Like other kinds of cover, the shield has to have a location
relative to you on the battlefield. When you use the shield for
cover, choose one edge of your space (not a corner). You have
total cover against any attack’s line of effect that passes
through that side of your space. If an attack’s line of effect goes
through the corner of the side of your space that the shield
blocks, you get cover from the shield (+4 AC, +2 on Reflex
saves) instead of total cover. If an attack’s line of effect passes
through a side of your space that the shield does not block, you
get no cover from the shield at all. To determine where the line
of effect enters your space, draw a line from the attacker’s
center to your center. Or, in the case of a magical effect, from
the effect’s point of origin and your center.
Once you claim cover from the shield, the shield keeps
blocking the side of your space that you chose until the
beginning of your next turn, when you can again decide
whether you’ll use the shield for cover. Once you choose the
side of your space that the shield blocks, you cannot change it
until your next turn.
You continue to threaten the area around you while you use
the shield for cover; however, it provides your opponents with
the same benefits you get. You cannot make attacks through the
side of your space that the shield blocks, and should you attack
through the corners of that space, your foe gets cover against
your attack. Since cover of any kind prevents attacks of
opportunity (see page 151 in the PH), the shield keeps you
from making attacks of opportunity in a pretty wide swath.
Total cover or cover from a tower shield has the following
effects in different situations:
- Magical Attacks: A tower shield’s effects on
magical attacks depend on the kind of magical attack.
Any attack aimed at your equipment is aimed at you.
If a magical attack has you as a specific target (that is
it does not merely affect the area that contains you
but is aimed right at you), the shield has no effect. All
rays fall into this category, as does any spell that has
a Target entry in its header and any spell that has an
Effect entry and affects creatures (provided, of
course, that the attacker can and does choose the
shield user as a target). Magical attacks that fill areas
(bursts, cones, cylinders, lines, emanations, and
spreads) are subject to all the rules for cover on page
151 of the PH. Such attacks are completely blocked
if line of effect between you and the attack’s point of
origin passes through the side of your space the
shield blocks. You get cover (+4 AC, +2 on Reflex
saves) if the magical attack’s line of effect passes
through the corner of the blocked side. Spread effects
reach around the shield if they normally would
extend into your space, but you still get a Reflex save
bonus for cover when they do. A gaze attack is
blocked if the shield would give you total cover
against attacks from the creature with the gaze attack.
If the shield gives you cover only, you’re still subject
to the gaze attack (although you could avert or close
your eyes to avoid the attack).
- Attacks of Opportunity: As noted earlier, cover or
total cover prevents attacks of opportunity. So you
could, for example, hunker down behind a tower
shield and pick up a weapon or rummage around in a
backpack and avoid attacks of opportunity against
you. If you’re moving while using the shield for
cover, things get a little more complicated. You must
determine whether the shield gives you cover (or
total cover) at the point during your movement when
you’d normally provoke an attack of opportunity.
Remember that attacks of opportunity are usually
resolved before the actions that provoke them. In
many cases, the shield won’t be positioned correctly
to protect you during your whole move.
- Charging and Bull Rushing: Opponents can charge
you while you claim cover from the shield. An
opponent moves as normal when charging you,
moving to the closest square from which a melee
attack normally would be possible. If the shield gives
you total cover from the attack, the attack
automatically fails. Foes can bull rush you normally,
moving right into your space in spite of the shield.
You normally get an attack of opportunity against
someone entering your space, but not if the shield
gives your foe cover or total cover.
- Grapple and Snatch Attacks: Total cover from a
tower shield blocks such attacks (the foe just can’t
get hold of you). The foe could, however grab the
shield. Conduct such attacks just like any other
grapple or snatch attack. Your foe can’t damage you
unless he pins you first. You can escape the foe’s
hold simply by dropping the shield (a standard action
since it’s strapped to your arm), so long as the foe has
not pinned you.
- Traps: Cover or total cover from a tower shield is
just as effective against a trap as it is against any
other attack.