I just read some fine print.
You can enter the sweepstakes by mail, even if you don’t finish 20 games.
You can only have one entry (20 games or hand-written) per-week.
SWEEPSTAKES
The Sweepstakes will consist of 750 First Prize drawings and 1,500 Runner-up Prize drawings each Week.
To enter for free without participating in the Tournament, hand-print your full name, complete address, day and evening telephone address, email address and date of birth on a 3" x 5" piece of paper and mail it in an envelope, with proper postage to:
<mark>Halo 4 Global Championship Tournament Sweepstakes</mark>
<mark>555 Monster RD SW</mark>
<mark>Renton WA 98057</mark>
Limit one (1) mail-in entry per outer postmarked envelope.
All mail-in entries must be handwritten.