行為人受徒刑之執行完畢，或一部之執行而赦免後，五年以內故意再犯有期徒刑以上之罪者，為累犯，加重本刑至二分之一。加重理由係因犯罪行為人之刑罰反應力薄弱，需再延長其矯正期間，以助其重返社會，並兼顧社會防衛之效果。同時排除過失再犯加重其刑，因後者難以確認其刑罰反應力薄弱。由此得出，累犯加重其刑的立論依據是特別預防觀點。然多數學者反對累犯加重其刑，因為違反罪責原則、與「行為刑法」相悖，以及宣告法定刑上限以上之刑違憲，故學理上欠缺正當性。何況，實務對行為人主觀危險性之評估與預測，尚未建立可受檢驗的科學判斷標準，可信度有待商榷。又現行法採刑罰與保安處分雙軌制，針對受處分人將來之危險性已有保安處分補充刑罰之不足，另採累犯制度屬可議。依學術通說有關刑罰目的之綜合理論，刑罰功能有二：一為強化一般大眾對法律效力的信賴，並產生威懾效果； 二為判刑的人因刑罰而產生未來遵守刑法規範的動力，並透過對其自由的限制，阻止繼續犯罪。但在罪責原則約束下，犯罪行為人的累犯可成為後罪法定刑範圍內的加重刑罰理由，卻不應該成為加重法定刑範圍的理由。累犯加重處罰規定不僅立論基礎受質疑，也欠缺實證研究的支持，建議刪除之，並回歸為量刑標準。

According to Criminal Code of the Republic of China, a person, who deliberately commit crimes with a minimum punishment of imprisonment within five years after having completed their total sentence or having been released under certain conditions after serving part of the sentence, is a recidivist. The punishment for a recidivist shall be increased up to one half. The main legislative reason for imposing a severer punishment for a recidivist is that the previous sentence could not create a deterrent or rehabilitative effect on the criminal, and thus the criminal justice system wishes to prolong their periods in the correctional institutions to enhance rehabilitative functions and safeguard social defence as well. Meanwhile, those who commit crimes negligently will be excluded from imposing server punishments because we hardly confirm whether the previous punishment caused effects on them. It can be referred that the harsher punishment for recidivists derives from the viewpoint of individual deterrence. However, most scholars oppose the justification for imposing severer punishment on recidivists because it neglects that punishment should be appropriate to the crime and that Criminal Code is based on the a person’s conduct. Additionally, to declare and impose harsher punishment than statutory punishment is unconstitutional. Under these circumstances, the punishment lacks legitimacy theoretically. Moreover, we haven’t established a testable scientific tool to evaluate and predict a person’s risk and dangerousness, and thus the validity of judges’ assessment is dubious. Furthermore, the current Criminal Code adopts not only penalties but also rehabilitative disposition execution, and thus the latter could be utilized for dealing with those who have future risk. Whether we need to enact additional punishments for recidivists in the Criminal Code is debatable. Most scholars believe that there are two major purposes of punishment. One is to strengthen the general public’s trust in the effectiveness of the legal mechanism, and thus they will be deterred from committing crimes. The other is to increase culprits’ willingness to obey the laws and prevent them from committing crimes continually by locking them up. Nevertheless, under the principle that punishment should be appropriate to the crime, recidivists could receive the harsher punishment only under statutory punishments, yet their repeated offending should not be a reason to impose longer sentences than statutory punishments on them. To sum up, to impose severer punishments on recidivists lacks legitimacy and empirical evidence, and thus this regulation should be repealed. Instead, the offenders’ recidivism should be taken as a criterion for sentencing standards.