1. The basic distinction between union extras and non-union extras is this: union extras get paid more but non-union extras often get more work. Union extras also get benefits, such as health coverage, and they are generally treated better on set.
2. SAG requires every film and TV show to have a minimum number of extras who are union members. Since union extras have a higher base rate of pay and receive more benefits, a production will usually only hire the minimum number of union extras and give all the rest of the jobs to non-union extras. This is why there is more work for non-union extras. SAG extras are always treated better, they get the best jobs and they get hired first, but there are fewer jobs to go around.
3. The first way to join the union is to work on three union vouchers. Whenever an extra is cast, whether union or non-union, a voucher is issued with necessary information, which is signed at the end of the day and submitted back to the casting company so that the extra can get paid. Union extras get union vouchers, and non-union extras get non-union vouchers. If a union extra is cast and the voucher is issued but then that union rascal doesn't show up, the voucher still has to be filled in order to meet the SAG minimum number. Therefore, they'll take one of the non-union extras and get him or her to work on the union voucher. Do that three times and you can join the union.
4. The second way to join the union is to be a non-union extra who is required to speak a line for some reason. Non-union extras are not allowed to say lines, but under certain circumstances it can become necessary for them to do so (though it's very rare). They then automatically can join SAG.
SoYouWanna know more? Check out our full-length article SYW be a movie extra?
