Official
Sandwich Law.

1. § 1.1
   Opposite means opposite. Both slices must sit at antipodal points: latitude flips sign, longitude moves exactly 180 degrees. "Roughly across the ocean" is a vibe, not an antipode.
2. § 1.2
   The Earth is a sphere by decree. On the real ellipsoid the through-planet distance varies from 12,714 km at the poles to 12,756 km at the equator, which would make "closest to the equator" the whole game. Therefore every Earth Sandwich is exactly 12,742 km thick by law. The true figure may be displayed as trivia; it may not be scored.
3. § 1.3
   Both ends need dry ground. Land at your feet, land at your antipode's feet. Ice sheets count as expedition-class ground (§ 4.3). Boats do not count. A floating bread board is a raft with delusions, not a sandwich end.
4. § 1.4
   Height is glory. A sandwich's elevation bonus is the elevation of end A plus the elevation of end B, in metres. Negative bonuses are fully legal: a below-sea-level sandwich is the world's smallest largest sandwich and shall be displayed with the respect and shame it deserves.

1. § 2.1
   Simultaneity is the point. Both slices must be in place at the same UTC instant, with an official tolerance of ±5 minutes. A sandwich assembled in shifts is a leftover.
2. § 2.2
   GPS time governs. Timestamps are judged on satellite-derived time (the capture clock synced against the Authority's servers, or a photo's GPS timestamp). Your phone's local clock is a known liar and is not consulted.
3. § 2.3
   No time travel. A photo whose claimed capture moment is later than its arrival at the Authority is rejected without appeal, but with admiration.

1. § 3.1
   Bread must be visible. Each photograph must clearly show the slice and the ground it rests on. The top-end slice lies face-down and the bottom-end slice face-up, so the planet is properly enclosed. (Which end is "top" is agreed between participants; the Authority observes strict neutrality on hemispheres.)
2. § 3.2
   Bread is defined generously. Loaf slice, flatbread, baguette section, tortilla — anything a reasonable person would put a filling on qualifies. Crackers are entertained on appeal. A picture of bread on a screen is not bread.
3. § 3.3
   No faces required. The rules demand visible bread, not visible people. Photographs containing identifiable bystanders will not be published.

Bread almost never lands on the mathematically exact antipode. Accuracy therefore has flavour, measured as the distance between one slice and the true antipode of the other:

Tiers are computed conservatively: the measured distance plus both phones' reported GPS accuracy radii. A phone reporting ±2 km does not earn artisanal credit, no matter how confident its owner feels.

Every submission carries one of three evidence grades, stated on its public record. Higher grades outrank lower ones at equal tier and bonus.

A submission is verified when a machine and a human independently agree. Any two judges applying this checklist to the same pair of photos must reach the same verdict:

1. § 7.1
   Both photos show bread on dry ground (§ 1.3, § 3.1).
2. § 7.2
   Governing timestamps fall within the same ±5-minute UTC window (§ 2.1, § 2.2).
3. § 7.3
   Distance to the true antipode, plus both accuracy radii, fits a tier in Article IV.
4. § 7.4
   The evidence grade matches how the photos were captured (Article V).
5. § 7.5
   Nothing in either photo prevents publication (§ 3.3, Article VIII).

Machine checks run first and produce written reasons. A human moderator confirms before anything becomes public. Failure at any clause is reported to the participants with the clause number, because rejection should at least be educational.

1. § 8.1
   Published coordinates are rounded to roughly 1 km. The world learns which hillside you sandwiched, never which doorstep. Exact coordinates and original photos remain private, indefinitely.
2. § 8.2
   Nothing appears on this site before a human has looked at it. Moderation gates the Authority's own leaderboard and gallery — and happens before first publication, not after complaints. Your photos and souvenir card are yours: sharing them anywhere else needs no review and never will.
3. § 8.3
   Either participant can withdraw. Each side of a sandwich keeps the right to pull their photo at any time, which unpublishes the pair — a sandwich needs both halves anyway.
4. § 8.4
   Metadata is stripped on publication. Public photo copies carry no EXIF data of any kind.