Once a beginning witch or
wizard has an understanding of the various kinds of spells that can be used in
his or her defense, these spell casters must learn to differentiate between
which spells are appropriate for a given situation. There may come a time when
offensive spells are not or are no longer useful in incapacitating the
opponent; nor are they useful when the caster is at a disadvantage due to a gap
in skill level from his or her opponent. In these scenarios, witches or wizards
must find a way to defend themselves against their opponents’ attacks. There
are two very basic ways in which a beginner can do this.  A witch or wizard could create a shield
against the opponent’s attack using Protego, or disarm his or her opponent
using Expelliarmus. The Shield Charm and the Disarming Charm form the
foundation of defensive spells that all beginning witches and wizards should
master. This section will focus on the Disarming Charm: how to cast it and its
various uses.

How to Cast Expelliarmus

The first component to
casting the Disarming Charm properly is to learn the incantation. As is the
case with many different spells, mispronunciation of the incantation can have
various adverse effects, including but not limited to setting the target aflame.
Since most spell work is subject to the adverse effects of mispronunciation, it
is important that a witch or wizard practice the incantation thoroughly,
ideally first without the wand, before attempting to cast it on an opponent.
The correct pronunciation is ex-PELL-ee-are-mus, and both articulation and
emphasis are important to correctly casting the spell.

The second component to
casting Expelliarmus is the wand movement. The wand movement for this spell is
not a precise pattern, and there have been differing reports for what movements
are the most effective. A small circular motion of the caster’s wrist has been
considered to lend more power to the spell, but this movement is not necessary
to casting the spell. In most cases, simply pointing the wand toward the target
is enough to cast the spell.

The previous two components
are required for the spell to be cast. The following components can affect the
strength of the spell and supplementary effects that occasionally occur.

Aim becomes a key factor in
a caster’s technique of casting the spell. Since wand movement is so minimal
and does not allow for a focusing of magical energy, the aim of the caster must
be precise in order for the effects of the spell to hit the intended target.
This lack of precise wand movement also puts a greater dependency on the
caster’s concentration. Concentration, working with the caster’s aim, focuses
the magical energy of the spell. The greater the concentration on both the
intended effects and the intended target the stronger the effects of the spell.
If aim or concentration is off, the effects of the spell can become useless or
minimized.

Effects of Expelliarmus

When the spell is cast
properly the opponent or target should be disarmed and relieved of his or her
wand, thus making the opponent less of a danger to the caster. There have been
records of the charm manifesting in a red light and these occasional colour
manifestations are likely a result of the spell’s power due to intense
concentration. When the spell is cast weakly, the effects may be diminished to
the point that the opponent remains armed and is only knocked back a few paces.

In contrast, when the spell
is cast powerfully, the opponent may be disarmed as well as fall victim to
supplementary effects. These supplementary effects are generally considered to
be dependent upon the aim of the caster and whether the focal point of the
spell is on the wand or the body of the target. When the body takes the main
charge of the concentrated spell, the opponent may be knocked backward or down
in addition to being disarmed. When the wand is the focus of the spell, the
wand may be thrown a farther distance away from its owner.

If the spell is not cast
properly, it may backfire on the caster, unintentionally disarming him or her.
This result, when it occurs in the midst of a real conflict, could be even more
harmful than the reduced effects of a weak charm.

There have been records of
the effects that may occur when multiple witches or wizards cast the Disarming
Charm on the same opponent simultaneously. Multiple incantations of the same
spell can exaggerate the effects of the spell, in some cases leaving the
opponent unconscious.

Uses of Expelliarmus

Expelliarmus can be used in
many different scenarios. It is a foundation defensive spell that can be called
upon when a witch or wizard is in even the most intense conflicts, or fallen
back on when in a bind. It is a useful spell for any dueling situation.

While beginning wizarding
students are not yet required to understand the formal dueling techniques,
looking to the future is never discouraged. The Disarming Charm can be a handy
spell in any dueler’s arsenal. For formal and recreational dueling, using
Expelliarmus effectively can, depending on the limits set for the duel, render him
or her unable to continue and signal the end of the duel (by being disarmed).
Since recreational duels can be used for training purposes, using Expelliarmus
in that setting may prepare a witch or wizard for using it in other more
precarious situations.

Many scenarios in which
Expelliarmus can be used tend to resemble the conditions of a duel. While not
dictated by the rules and regulations of a formal duel, many real life
situations of conflict between individuals involve the same situations that
would be present in a formal duel. When a witch or wizard is heading off
against an individual opponent, Expelliarmus can be used to distract, delay or
defeat the opponent depending on the individual situations.

Expelliarmus can be used as
a distracting agent, by casting the spell quickly and unexpectedly to throw off
an opponent. When an opponent is at an advantage or even if the opponent has a
greater skill level than the caster, a carefully placed Disarming Charm may
catch the opponent off guard momentarily—even if the opponent is not
disarmed—giving the caster an edge for a brief time.

By effectively casting Expelliarmus, a caster
can disarm his or her opponent in order to delay the opponents’ attack. The
opponent would be forced to take the time to retrieve his or her wand, giving
the caster enough time to recoup and continue the duel- or to escape. In an
intense or unrelenting struggle, buying even a minute’s time can give the
caster the opportunity to regain the upper hand.  Sometimes a few extra seconds are all a witch
or wizard needs, and Expelliarmus can be the means of obtaining those precious
moments.

Expelliarmus, despite being
a simple spell, can also bring about the defeat of a caster’s opponent. A
strong, well-placed Disarming Charm may allow a caster to disarm their opponent
and then acquire the opponent’s wand. Sometimes, Expelliarmus may send the
opponent’s wand as far as the caster’s own hand. This result will leave the
opponent unarmed and perhaps force him or her to surrender. It may also give
the caster the time to cast a spell to incapacitate or otherwise defeat his or
her opponent in a different manner. 

The Disarming Charm is a
useful spell to have mastered because of its multifaceted uses. It can be used
when more complex spells are not known or when there is not enough time for
them to be cast. It is a spell that the most amateur witch or wizard can
perform in the thick of a struggle or duel. Whether the opponent may be
preparing to cast the Stunning Spell or the Killing Curse, Expelliarmus can be
effective in removing the wand and thus the ability of the opponent to cast any
spell. Even the most talented witch or wizard may need to fall back to the
basics in some situations.

Thus, the true lesson of
Expelliarmus is this: a witch or wizard should master and understand the
foundational spells, the basics, before moving on to more complex spells
because sometimes the simplest spells may have the most value.