In the Philippine legal system, Unjust Vexation is often described as a "catch-all" provision for conduct that causes annoyance, irritation, or mental distress to another person, but does not constitute a more specific crime like physical injuries or threats. It is penalized under Article 287 of the Revised Penal Code (RPC), as amended by Republic Act No. 10951.

The Legal Elements

To successfully prosecute a case for Unjust Vexation, the prosecution must establish the following elements beyond reasonable doubt:

The Offender performs a human act: This refers to any overt act—whether physical, verbal, or through gestures—directed at the victim.
The act causes annoyance, irritation, torment, or distress: The primary effect of the act is the disturbance of the victim’s peace of mind.
The act is unjust: The behavior must have no legitimate purpose or legal justification. It is done with "wrongful intent" or malice.
The act does not constitute another crime: If the act already falls under Grave Threats, Slander, or Physical Injuries, it should be filed as such. Unjust Vexation is residual in nature.

The "Irritation" Standard

The Supreme Court has clarified that the main yardstick for Unjust Vexation is whether the act would cause a person of ordinary feelings to experience mental suffering. It is not measured by the specific sensitivity of the victim, but by a general standard of what is socially acceptable.

The Filing Process: Step-by-Step

1. The Barangay Conciliation (Pre-requisite)

Since Unjust Vexation is a light offense, it generally falls under the jurisdiction of the Katarungang Pambarangay.

Action: You must first file a complaint with the Lupon Tagapamayapa of the barangay where the incident occurred.
Requirement: If no settlement is reached, the Barangay Captain will issue a Certificate to File Action. Without this certificate, a court may dismiss the case for being premature (unless the parties live in different cities/provinces).

2. Filing the Complaint-Affidavit

Once you have the barangay certificate, you must go to the Office of the City or Provincial Prosecutor.

Documentation: You will submit a "Complaint-Affidavit" detailing the "who, what, when, where, and how" of the incident.
Evidence: Attach supporting evidence such as CCTV footage, screenshots of messages, or Judicial Affidavits of witnesses.

3. Preliminary Investigation or Summary Procedure

The Prosecutor’s Role: The prosecutor determines if there is probable cause to believe the crime was committed.
Counter-Affidavit: The respondent (the person you are accusing) will be given a chance to submit their defense.
Information: If the prosecutor finds merit, they will file a formal "Information" in court.

4. Court Proceedings

Under the Revised Rules on Summary Procedure, cases of Unjust Vexation are handled expeditiously.

Arraignment: The accused enters a plea (Guilty or Not Guilty).
Trial: Both sides present evidence. Because it is a summary procedure, the court often decides based on affidavits and position papers to avoid lengthy oral testimonies.

Penalties and Prescription

Under Republic Act No. 10951, the penalties for Unjust Vexation have been updated:

Penalty: Arresto menor (1 to 30 days of imprisonment) or a fine ranging from PHP 1,000 to PHP 40,000, or both, at the discretion of the court.
Prescription Period: The case must be filed within two (2) months from the time the victim discovered the act. If you wait longer than 60 days to initiate the process, the crime "prescribes," and you lose the right to sue.

Key Considerations

Intent Matters: The defense often argues that the act was accidental or done in the heat of the moment without the specific intent to vex.
Civil Damages: Aside from criminal penalties, the victim can also pray for moral damages and attorney’s fees.
Gender-Based Vexation: If the vexation involves sexist remarks or unwanted sexual advances in public spaces or online, it may be filed under the Safe Spaces Act (Bawal Bastos Law), which carries heavier penalties than the Revised Penal Code.