On paper it looks good, but in practice the rule of law in Vietnam is a fickle beast. Local officials interpret the law any way it suits them, often against the wishes of Hanoi. There is no independent judiciary. Not surprisingly, most legal disputes are settled out of court. In general, you can accomplish more with a carton of cigarettes and a bottle of good cognac than you can with a lawyer.
The drug trade has made a comeback in Vietnam. The country has a very serious problem with heroin these days and the authorities are clamping down hard: in 2001 alone, the government executed 55 people for drug offences.
Marijuana and, in the northwest, opium are readily available, but giving in to this temptation is a risk. There are many plain-clothes police in Vietnam and, if arrested, the result might be a long prison term and/ or a large fine.
Vietnamese police are the best that money can buy. Police corruption is an everyday reality and has been acknowledged in official newspapers. If something does go wrong, or if something is stolen, the police can't do much more than prepare an insurance report for a fee.
Hanoi has warned all provincial governments that any police caught shaking down foreign tourists will be fired and arrested. The crackdown has dented the enthusiasm of the police to confront foreigners directly with demands for bribes, but it still happens in more out-of-the-way places.