The party list is omitempty, so a solo run and a game box too old to push
seats reach Pete as the same empty slice, and those two want opposite
buttons. Pete's page was reading the empty one as "solo, therefore leader"
and offering a party member the button that throws away everyone's day.
One boolean, set on every sheet a build makes — in town, solo, or seated
with three others. It says something about the sender, never about the
character, so it is set unconditionally: a conditional flag would read as
"this player is solo" and land straight back in the hole it closes. An
older build sends no key at all, which decodes to false, which is the
answer Pete wants when it cannot tell.
Pete's half shipped already and withholds the button until this arrives.
Verified end to end against a local Pete, not just in tests: a solo leader
on a live expedition gets "Call the whole thing off" back, a member still
gets "Turn back alone" and never the abandon, and stripping the flag from
the same push takes the solo button away again.
Party seats ride the roster detail, beside the supply and threat numbers the
same expedition already publishes. Leader first, the hireling named without a
token he has no board row for, and an opted-out player's seat kept and
anonymised — dropping it would make a party of three read as a pair while the
burn rate and enemy scaling beside it still felt three bodies.
The board itself was wrong about this: it resolved an expedition with a lookup
keyed on dnd_expedition.user_id, which is blind to members, so for the whole
life of N3 parties a seated player has shown as idle in town while standing in
a dungeon.
Pets also send the engine's XP threshold for their current level band, so the
web can draw progress without keeping a copy of a curve that would drift.
prosolis