Let's finish the topic of spells and spell-like abilities by going over the differences between them. Then you can see some options for how to (and how not to) disrupt spell-like abilities.

Differences Between Spells and Spell-Like Abilities

A spell-like ability is not a spell. (If it was, it would simply be called a spell.) Important differences between spell-like abilities and spells include the following:

• A spell-like ability has no verbal, somatic, material, focus, or XP components. Using a spell-like ability is a purely mental action, albeit one that requires enough concentration to provoke attacks of opportunity. It is quite possible, however, that a creature using a spell-like ability might add some gesture, word, or flourish just for dramatic effect.
  
  
• A spell-like ability cannot be used as a counterspell, and it is not subject to counterspells. A counterspell involves recognizing a spell as it is being cast, then quickly altering that same spell so as to create an opposite effect that cancels out the original spell. A spell-like ability is essentially hardwired into its user's psyche, and its power is released mentally. The process is sufficiently different from spellcasting so it that doesn't allow a foe to identify the spell-like ability, and a counterspell cannot interfere with the spell-like ability's magical energy as it can with a spell. As noted earlier, a spell-like ability is subject to dispelling (provided the spell it duplicates is subject to dispelling). When a spell-like ability can be dispelled (as most of them are) one can effectively counter them with a dispel magic spell. While spell-like abilities are not normally subject to counterspells, dispel magic is not really a counterspell. When you use dispel magic as a counterspell, what you're really doing is casting a quick, targeted dispel effect at the correct moment to negate the enemy spell and not creating an opposite magical effect that cancels your enemy's spell.
  
  
• A spell-like ability is not subject to spell failure. A creature using a spell-like ability that duplicates an arcane spell doesn't have to worry about arcane spell failure from armor it wears (assuming it's wearing armor) or about spell failure from any other source or condition (such as deafness).
  
  
• A spell-like ability need not be prepared in advance. As noted earlier, a spell-like ability is hard-wired into the user. A creature with a spell-like ability doesn't have to do anything to get its daily allotment of spell-like abilities. It does not need to study, pray, meditate, or even rest.
  
  
• A spell-like ability is not subject to metamagic. For many of the same reasons a spell-like ability cannot be countered, it also cannot be modified through metamagic in any way. Some creatures have special feats that allow them to duplicate the effects of metamagic on their spell-like abilities (such as the Quicken Spell-Like Ability feat). It's also possible for a creature to have a spell-like ability that duplicates spells already altered by metamagic. For example, the archmage prestige class allows a character to make a spell modified by metamagic into a spell-like ability.

Disrupting Spell-like Abilities

In most cases, one can disrupt a foe's spell-like ability in exactly the same way one disrupts a spell. For example, a creature's opponents can ready attacks to disrupt its spell-like abilities, and if they hit the creature while it uses a spell-like ability, they may cause the ability to fail. The DC for the creature's Concentration check is exactly the same as it would be if the creature were casting a spell. Likewise, if the creature tries to use the spell-like ability defensively, the ability doesn't work unless the creature makes a successful Concentration check.

For instance, suppose that a group of adventurers closes in on a pesky vrock demon and begin pounding it to bits with their melee attacks (as adventurers usually do when they get the chance). The vrock decides to escape via its greater teleport ability. The vrock must use a standard action to trigger the ability, and the action provokes an attack of opportunity from all foes that threaten the demon at the time. Let's say the vrock is canny enough to use a 5-foot step to move away from all but one foe (Sondranna the barbarian). Let's also say that Sondranna hits with her attack of opportunity and deals 16 points of damage with her greataxe. Unfortunately, the vrock has damage reduction 10/good, and Sondranna's greataxe, though magical, is not good, so Sondranna's blow only deals 6 points of damage to the demon. The demon still took some damage, however, and must make a Concentration check to finish using the ability. The DC for the vrock's Concentration check will be the same as if it were damaged while casting a greater teleport spell: 10 + spell level (because the vrock was "casting" when the distraction occurred, see the Concentration skill description) + damage dealt. In this case the DC is 23 (10+7+6). With the vrock's Concentration score of +20, its check probably will succeed.

Later, the vrock returns with a friend in tow and the pair resume the attack on the party. After several rounds of violent maneuvers, the party corners both vrocks, and the two demons decide to tough it out and fight. One vrock, however, decides to use its mirror image spell-like ability to help it avoid a few hits from Sondranna and her allies. The vrock decides to use the ability defensively to avoid a hail of attacks of opportunity. Because the vrock is using the ability defensively, it must succeed at a Concentration check to successfully use the ability. The DC for the check is 15 + the spell level. Mirror image is a 2nd-level spell, so the DC is a mere 17. The vrock will succeed with this check automatically thanks to its Concentration score of +20 (there's no automatic success or failure on a check as there is with a saving throw or attack roll, see page 63 in the Player's Handbook), and so the vrock's use of mirror image won't provoke any attacks of opportunity this time. However, let's suppose that Sondranna has seen this trick before and that she has readied an action to disrupt the vrock's magic use. The vrock's defensive power use won't interfere with the readied action (it only keeps the power use from provoking attacks of opportunity). Furthermore, let's assume Sondranna has received a bless weapon spell for her greataxe, making it a good weapon that bypasses the vrock's damage reduction. Sondranna hits and deals 18 points of damage to the vrock; the mirror image is not yet in effect because Sondranna's readied action interrupts the magic use, so there's no chance that Sondranna's blow will strike an image instead of the vrock. The vrock must make a Concentration check with a DC of 30 (10+2+18).

Suppose the check fails. This use of the vrock's mirror image power is wasted. The vrock can use mirror image at will, however, so it can try again next round. The vrock used a standard action to employ its mirror image power, so it's pretty much done for this round. It could take a move action, but it cannot attack or use another spell-like ability (both of which also would require standard actions). It could take a move action, but it declines to do so, preferring to keep its foes within reach.

Coming in Part Three of All About Spell-Like Abilities

Next time Skip tells you how to determine the spell level and version of a spell-like ability.

About the Author

Skip Williams keeps busy with freelance projects for several different game companies and has been the Sage of Dragon Magazine since 1986. Skip is a co-designer of the D&D 3rd Edition game and the chief architect of the Monster Manual. When not devising swift and cruel deaths for player characters, Skip putters in his kitchen or garden (his borscht gets rave reviews).