When registration closes, all 48 half-hour slots are assigned automatically to maximise total kingdom points — there is no first-come advantage. The order is:

1. Priority ranking. Everyone is ranked by score — your committed speedup minutes weighted by the highest troop tier your TC can train. More speedups and a higher tier mean a higher rank.
2. Earliest preferred slot. Going down the ranked list, each player is placed in the earliest of their preferred times that is still open.
3. If your picks are full. If every time you selected is already taken by higher-ranked players, you get the closest open time to your preferences instead.
4. Waitlist. If all 48 slots fill before your turn, you go on the waitlist in rank order and move up if someone drops.

Tip: pick as many preferred times as you can — more options means a better chance of landing one you want instead of being placed near it.