| name | greed-island-cards |
| description | Reference for the Greed Island card system - vnum mappings between restricted cards and their physical items, the make_card conversion engine, player commands (gain/change/book), auto-conversion and timed-reversion rules, and where player-facing text must stay in sync. Use when working on card mechanics, ITEM_CARD/ITEM_SPELLCARD/ITEM_RESTRICTED items, or the 653/654 zone card files. |
The Greed Island card system (detailed)
The card mechanic is the heart of the game and its logic is spread across a few hooks. Reference map:
Item types (structs.h): ITEM_CARD 24 (free/unrestricted card), ITEM_SPELLCARD 25 (cast on use, consumed), ITEM_RESTRICTED 26 (the numbered 000–099 collectible cards). IS_CARD(obj) (utils.h) = any of those three.
vnum mappings
- Restricted: card vnum ∈ 65300–65399 ↔ physical item = card + 100 (65400–65499). The restricted card's
GET_OBJ_RENT holds the global copy limit (the "-N" in SS-1, A-17).
- Free cards (type 24): the physical-item vnum is stored in the card's
GET_OBJ_RENT (e.g. free cards in lib/world/obj/400.obj, their items in 401.obj). A freshly-created free card stamps the source item's vnum into GET_OBJ_RENT.
- Voucher: a type-24 card at vnum 65535 flagged
ITEM_QUEST; appears when a restricted card's global limit is reached.
The conversion engine: make_card(ch, obj, show) in act.item.c is a single bidirectional function — it decides direction from the object's type/vnum (item→card creates/loads a card; card→item reads the stored target). show only controls the room message. Returns 1 on success, 0 if nothing happened. ITEM_NOGAIN (extra flag) marks "already converted, cannot convert again" and is never cleared.
Special cases are inserted at act.item.c ~line 1919 (after the Recycling Room block and the Perfect Memory Studio block, both inside the ITEM_RESTRICTED branch). The newly-created item is in the local variable card. Use obj_to_obj(child, card) to pre-load objects into a container before it reaches the player (see Hormone Cookies #33, vnum 65333 → loads 20 cookies vnum 65534 into box 65433).
Player commands
gain (do_gain): bidirectional convenience verb — card→item, item→card, and casting spell cards (needs the book/PLR_BOOK active via the book command).change (do_change): item→card only, for ordinary items. This is the manual path for common loot.book (do_book, act.movement.c): summons the binder container (vnum 3203) via the ring (3202); 45 free slots + 100 restricted (deduped by vnum).
Auto-conversion rule (current): on pickup/give-from-NPC/steal, an item auto-converts to a card only if it becomes a restricted card — gated by GET_OBJ_VNUM(obj) > 65300 && != 65535 at the call sites in act.item.c (perform_get_from_room, perform_get_from_container, perform_give) and act.other.c (do_steal). Ordinary items never auto-convert; the player uses change.
Timed auto-reversion: second_update (limits.c) decrements each loose card's GET_OBJ_TIMER (set to 62 on creation / on binder put-get); at 0 a card outside binder 3203 reverts to its item (and is flagged ITEM_NOGAIN). Cards inside the binder are exempt — that's the incentive to store them.
Player-facing text to keep in sync when card behavior changes: NPC Eta (mob 1401) triggers 1419/1496 in lib/world/trg/14.trg; the notice sign obj 3298 in lib/world/obj/32.obj; help entries GAIN, CHANGE, CARDS, BOOK in lib/text/help/help.hlp; and lib/text/info.
