Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_30 (games INTEGER, win_percentage VARCHAR, Pwin_percentage VARCHAR, — VARCHAR, term_ VARCHAR, c_ VARCHAR)

### Question ###
What is the sum of the game with a PWin% of —, Term [c] of 1987–1988, and Win% less than 0.506?

### Accurate SQL ###

SELECT SUM(games) FROM table_name_30 WHERE Pwin_percentage = — AND term_[c_] = "1987–1988" AND win_percentage < 0.506