strategy-map.md

The map strategy

One strategy covering maps, charts and Valdo maps. What every strategy shares — bounds, options, merged stats, derived numbers — is in item-layer.md.

item/plan's map strategy (plan_map, add_map_pseudo) is Strategy::Map, and it is the one strategy that searches on none of an item's affixes. A map's prefixes and suffixes are re-rollable with a single Chaos Orb; the buyer is choosing how dangerous a map they want, not which affix it has, and a query naming them would find the one copy in the league that rolled that set. So they are not filters and not notes either — they are left out on purpose, in front of the reader (the item card beside the panel), and "unrecognised modifier: Players have 25% less Accuracy Rating" would charge the check with failing at something it never attempted. What is searched instead:

• Which area it is. Every ordinary map now shares the one base type, printed as Map (Tier 16), so the tier is the whole of what tells two apart; parse_header takes it off into Item::map_tier because no lookup knows the parenthetical, and draw_name_plate puts it back on screen. The filter is map_filters.map_tier with min == max: a tier-16 map is a different area from a tier-14 one, not a better one. A map that names its own area instead (Shaper Guardian Map, Nightmare Map) prints no tier and is matched by that name alone. A unique map is its name plus that tier; its own modifiers are on every copy. The map discriminator the bundle's Map record carries is load-bearing here rather than a tie-break: a query sending the type as a bare "Map" is accepted and matches nothing, which reads as an empty market rather than as a search that could not be built — so a bundle without that record gets a note instead.
• What the map does for you. map_iiq and map_packsize on by default, map_iir off — rarity is a preference, and imposing it drops the cheaper copies of the same map. All three come off the game's own property lines.
• The four drop bonuses a Maven's chisel adds — More Maps, More Scarabs, More Currency, More Divination Cards — which the game also prints as properties and which trade has no map_filters entry for. They are pseudo.* stats (pseudo_map_more_map_drops and its three siblings, which is all of them in /api/trade/data/stats), enabled when present.
• How many affixes it has, as a total, and only on a corrupted map: six is what every rare map has, and eight is what only corruption allows and most of what such a map is worth. pseudo.pseudo_number_of_affix_mods. The side of the pool is printed only by Advanced Mod Descriptions, so with that off there is no count to give and the plan says so rather than counting zero. Continuation lines are counted out — one affix can print two.
• The implicit and any enchant, on by default, and on presence rather than on their numbers — see the bound rule in item-layer.md, which a map is exempt from needing evidence for. The implicit is the one modifier a currency cannot re-roll, and it is what names the boss, the influence or the memory.
• Blight, which is a filter and never a type. The base line is the only place the clipboard says so — Blighted Map (Tier 12), Blight-ravaged Map (Tier 16), no flag line and no property — so parse_header sets Item::blighted / blight_ravaged off it and resolve_base then points the base at the ordinary Map every other one shares. Sending "Blighted Map" as the type is accepted by the site and matches nothing at all (measured: 0 listings against 1449 for the Map base plus map_filters.map_blighted at tier 12), and no bundle carries a base under that name either. The two flags are mutually exclusive, so neither is ever asked for in the negative: a blighted map's own search already excludes the ravaged ones.

Charts

A chart is a map under another name and shares the strategy (plan_chart), which is the point rather than a shortcut: a Deepwater chart is an area with rolled danger and rolled rewards, its prefixes and suffixes are the danger a buyer is choosing among rather than the thing being bought, and trade puts it in the same filter group — map_filters is titled "Map/Chart Filters" for that reason. So the affixes are left out exactly as a map's are, and four things are added on top:

• Which area it covers. The game prints it as the leading prose line of the property block ("Seafloor Ridges"), i.e. Item::type_line, and trade takes it as the type — as an option carrying the chart discriminator, whose value is the area's internal id (SeafloorRidges). The bundle carries those records, but only under that id and with no display name anywhere on them, so chart_area_key turns the printed name back into one: apostrophes go, spaces and hyphens are word breaks, every word is capitalised ("Brine King's Domain" → BrineKingsDomain, "Clam-infested Shelf" → ClamInfestedShelf). That convention is only ever a lookup key — a record has to come back under it carrying the discriminator, or the search falls back to the chart's own base type ("Coral Reef Chart", which is a real search and simply a coarser one) plus a note. A wrong guess therefore costs breadth, never correctness.
• The area's level, map_filters.area_level, exact for the same reason a map's tier is: a level 83 area is a different area from a level 78 one, not a better one. Measured: 5526 listings at exactly 83 against 10000+ for the area alone, so it does discriminate.
• The shape — chart_shape, whose five ids are 1–5 for End/Corner/Straight/Junction/ Crossing. The game prints the option's own text, which is what makes the join possible; sending that text answers {"code":2,"message":"Invalid chart shape"} and fails the whole search, so it is a table in plan_chart copied from /api/trade/data/filters, the same closed-vocabulary argument as status_options.
• The sulphur ("Dead Man's Sulphur: +45%") as chart_sulphur, a floor and ticked: it is the league's own currency and therefore what the area is run for, so the same reasoning as a map's quantity rather than as its rarity.

Its voyage modifier needs nothing new — it is an implicit, so the map strategy already enables it, including on a chart nobody has sailed yet, which prints only the promise of one ("Voyage Modifier will be revealed once Charted"). That promise is a real stat with a real trade id, not prose, and a buyer choosing between a revealed and an unrevealed chart is choosing on exactly it.

Valdo maps

A Valdo map is the one map that is none of the above (plan_map's reward branch). It is bought for the unique it pays out, its quantity and pack size come from unique modifiers rather than from an affix roll, and so those are offered rather than imposed — they say nothing about which Valdo map a buyer wants. What is searched is map_filters.map_completion_reward, an option over the unique list: the game prints the payout as Reward: Foil Hrimsorrow, where the foil is the reward's own variant, and sending that whole string answers {"code":2,"message":"Unknown reward output provided"} — which fails the entire search rather than widening it. So find_unique_in takes the longest run of those words that names a unique the bundle knows, and a reward it cannot name becomes a note instead of a guess. The Reward property is also the marker: no other map prints one.

The other half is the only thing anything here is searched on in both directions. Whether dying in the map sends the character to the Void is what a buyer picks on, and a map that voids is a different item from one that does not — so the copy in hand decides which question is asked: present, and the search asks for it; absent, and it asks for the absence. Leaving it open prices the two together. That is StatFilter::negated, which build_query sends as a second stat group of type not beside the and one, carrying an id and no bounds. Measured on the same reward: 133 listings that void against 101 that do not.

Two things this needed elsewhere. StatFilter::mod_index is an optional now, because a pseudo total has no single modifier behind it; anything walking back to Item::mods has to check. And SearchPlan::rarity carries the trade rarity option, because a unique map is planned as a map — reading the option back off the strategy, as build_query used to, searched it among the rares. It defaults to nonunique, since an empty one is a search across both markets at once and nothing here ever means that.