Green card lottery applicants must meet some eligibility requirements whether they are living in the USA or in another country. This is clearly given in the instructions which used to be published by the US State Department.
As per it all the participants must be native of any of the country that is listed by the State Department as eligible countries. You can claim nativity by other means too. Read the dv lottery Instructions for the FY 2018.
Must have completely passed the High School certificate with all the compulsory subjects after attending junior and high school for 12 years, which is equivalent to the U.S High school education certificate. Most of the countries are accepted with GCE A/L and WAEC education certificates.
Or can proof that you have 2 years of working experience within the last 5 year period after learning and training the job for a period of 2 years. Check the draw's instructions for more information. It is very rare to qualify with the work experience from Africa and the Asia region.
If you are a Green card lottery winner at the time of the interview, you must proof your medical fitness according to the USA requirements.
You must provide a clean police certificate.
Winners must provide an affidavit of support from a person who is living in the USA as citizen or LPR holder (Green card) along with the required personal documents of that person to the interviewing consular office on the day of your interview.
Single unmarried person can submit only one entry.
It is not necessary to get married to participate in this lottery.
A married person must include his/her spouse and all the children who are unmarried and under the age of 21. Those children who are USA citizen or LPR holders must not be included in this lottery.
Don't participate in this visa lottery program, if you are banned by the US Government for life time for previous visa fraud attempt.