A more thorough explanation:

Special pleading is a legal term that refers to the common-law system of pleading. This system required parties to exchange a series of court papers, such as replications, rebutters, and surrebutters, setting out their contentions in accordance with hypertechnical rules before a case could be tried. Often, cases were decided on points of pleading and not on the merits.

Special pleading can also refer to the art of drafting pleadings under this system or an instance of drafting such a pleading. It can also refer to a responsive pleading that does more than merely deny allegations, as by introducing new matter to justify an otherwise blameworthy act.

Another meaning of special pleading is an argument that is unfairly slanted toward the speaker's viewpoint because it omits unfavorable facts or authorities and develops only favorable ones.

Example 1: In a court case, the defendant argues that they should not be held responsible for a car accident because the other driver was texting while driving. However, the defendant fails to mention that they were also speeding at the time of the accident. This is an example of special pleading because the defendant is omitting unfavorable facts to make their argument seem stronger.

Example 2: A student argues with their teacher that they should not receive a failing grade because they were going through a difficult time at home. However, the student fails to mention that they did not turn in any assignments and missed several classes. This is an example of special pleading because the student is omitting unfavorable facts to make their argument seem stronger.

These examples illustrate how special pleading can be used to unfairly manipulate an argument by omitting unfavorable facts or authorities and developing only favorable ones.