.....Drop-in play times are times when the courts are reserved for social play by all club players that shows up. Generally, when a lot of players show up, players will tend to split up by ability, but you will usually get quite a few chances to play with players both better and worse than yourselves.
.....The idea is have some times where players can get together with and meet other players of all abilities without having to prearrange a match. Players should player no more than 2 matches when others are waiting with at least 2 players or more rotating out after each match. Each club should establish there own procedures to be followed when players are waiting.
.....While you generally shouldn't need to be particularly good to play drop-in, you should know the rules, and be generally able to at least hit the ball.