fix: casino stake preservation, world state reconciliation, casino game registration

1 files changed, 11 insertions, 5 deletions

diff --git a/building_guide/rooms.md b/building_guide/rooms.md
index c70b379..719c09e 100644
--- a/building_guide/rooms.md
+++ b/building_guide/rooms.md
@@ -357,11 +357,17 @@ casino configurations. Raw file editing is not a validated save endpoint.
 - IDs must be nonempty, have no surrounding whitespace, and be unique across
   the room's tables and machines (including legacy slots table entries).
 - Supported table games are `blackjack` and `baccarat`; machines use `slots`
-  with the optional variant `huff_and_even_more_puff`.
-- Only one table/machine per game is addressable: a room is addressed by game
-  name (`play blackjack`), so a second entry for the same game, or the same
-  machine variant (including a legacy slots table alongside a slots machine),
-  is rejected as unreachable content.
+  with the optional variant `huff_and_even_more_puff`. A machine variant is
+  registered in Go (`slotVariants` in `internal/casino/registry.go`); naming an
+  unregistered variant is a validation error.
+- A multiplayer table is addressed by its game name (`play blackjack`), so a
+  room may host only one table per game; a legacy slots table still collides
+  with a slots machine.
+- A machine is addressed by its `variant` when one is declared, so a room may
+  host several variants of one game, each reached by its own variant name. A
+  bare game name addresses a machine only when it is the sole machine of that
+  game (or declares no variant). Two variant-less machines of one game, or two
+  machines sharing a variant, are rejected as unreachable duplicates.
 - Omitted/zero numeric values keep their existing defaults. Negative bets,
   timers, seat counts, split counts, decks, and payouts are rejected.
 - An explicit `max_bet` must be at least `min_bet`. An omitted or zero