DUI (driving under the influence) penalties range in severity depending on a number of factors, as well as individual state laws. While all states follow the national 'per se' law of a blood alcohol level (BAC) of .08% constituting a DUI charge and zero tolerance for those under 21 convicted of a DUI, each state also applies there own set of DUI laws. That said, most penalties fall in line with the same level of severity conditions. These conditions include how high a BAC reading was, how many prior DUI convictions a driver has and if there was an accident or any fatalities because of driving under the influence. Accordingly, penalties range from minor misdemeanors and alternative sentencing to suspended licenses to life in prison and massive fines. Additionally, several states employ unique penalties such as interlock ignition devices, which limit drivers who have been drinking from starting their cars through a breath analyzer system, and 'DUI' license plates that mark convicted DUI drivers as such on the road.