A lay judge, sometimes called a lay assessor, is a person assisting a judge in a trial. Lay judges are used in some civil law jurisdictions. Lay judges are appointed volunteers and often require some legal instruction. However, they are not permanent officers. They attend proceedings about once a month, and often receive only nominal or "costs covered" pay. Lay judges are usually used when the country does not have juries. Lay judges may be randomly selected for a single trial (as jurors are), or politically appointed. In the latter case they may usually not be rejected by the prosecution, the defense, or the permanent judges. Lay judges are similar to magistrates of England and Wales, but magistrates sit about twice as often.