You can challenge teams 50% of your rank above you plus 2 positions.

If you win a defending match you are protected for 30m (no one will be able to challenge you).
If you win a challenging match you are protected for 15m (no one will be able to challenge you).
If you lose a defending match you are vulnerable for 15m (you will be unable to challenge).
If you lose a challenging match you are vulnerable for 30m (you will be unable to challenge).
You cannot play the same team twice in a row.
Time given to accept a match: 24h
Team members required to challenge: 4
Players are allowed to be in 1 team at a time

This is a TURBO ladder, protected/vulnerable times are greatly lowered and matches can be offered/accepted with only 15 minutes notice.