Scenario Catalog — Authored Display Copy¶

Author: railroad-historian (M18 P1). This is the player-facing display copy for the two genuinely-playable scenario seeds, plus a one-line rationale per field so game-dev can wire the catalog knowing why each label was chosen. Ground truth is the seed data (data/scenarios/<id>/economy.json, rivals.json, map) as of the m18-titlescreen branch; period sourcing is at the bottom.

Scope note: these two are the only real player-facing seeds. Ignore the michigan_lp_1920s legacy test seed and the m14f_churn_fixture throwaway — they are not catalog entries.

A word on the two internal company names. The seeds ship different playerCompanyName values ("Great Lakes Railway" for the canonical seed, "Great Lakes Belt Railway" for the contested one). The displayName below is the scenario title the player picks from the catalog — deliberately distinct from the in-fiction company name, which is what the player later runs.

Seed 1 — `michigan_1920s` (canonical)¶

displayName:

Great Lakes, 1920: A State in Transition

description:

Michigan, 1920. The white-pine boom is a generation gone, leaving the northern counties cut over and thinning; the Copper Country up north has crested and begun its long slide; and down in Wayne County the automobile is turning Detroit into the fastest-growing industrial city in America. Across all 83 counties the Pere Marquette, Michigan Central, Grand Trunk Western and a dozen lesser roads already work the rails. Found your railway on $2,000 and a promoter's nerve, and build a road that outlives the timber and rides the auto boom.

difficulty: Standard

Rationale: This is the baseline road. Rivals exist and hold territory (Pere Marquette / Michigan Central / GTW / GR&I are LARGE; Ann Arbor and Detroit & Mackinac MEDIUM; DT&I SMALL, plus the UP extraction roads), but the competitive model here is static — no shared-corridor churn, no seasonal demand rotation (economy.json ships no rotation block, so rotation is inert). The pressure is spatial and economic (pick growing regions, avoid the declining cut-over/copper counties), not a live fight over the same freight. The $2,000 start plus a $10k founding target is a genuine but survivable shoestring. That combination — real rivals, no dynamic contest — is "Standard," not "Easy": a new player can lose here by expanding into the wrong (declining) geography.

Tooltip-worthy period detail (optional):

The seed's regional growth is frozen to the 1920 US Census and decays the right places: cut-over lumber counties and the copper range lose population year over year while Wayne/Detroit runs white-hot on the auto boom. Building north into the timber and copper country is building into decline — that's historically true, not a difficulty gimmick.

Seed 2 — `michigan_contested_1920s` (contested-corridor successor)¶

displayName:

The Southern Belt: Contested Corridors, 1920

description:

Southern Michigan, 1920 — the busiest railroad ground in the state. Here the Michigan Central and Grand Trunk Western run parallel trunk lines Detroit-to-Chicago, Henry Ford's Detroit, Toledo & Ironton funnels River Rouge auto traffic south to the Toledo gateway, and the Pere Marquette, Grand Rapids & Indiana and Ann Arbor jostle for the same tonnage: Battle Creek cereal, Kalamazoo paper, Grand Rapids furniture, Saginaw sugar and salt, and the swelling flood of Detroit automobiles. Demand swings with the calendar — a fall beet campaign, a deep-winter lake-ice cut — and every good corridor is already somebody's. Fight for the freight.

difficulty: Hard

Rationale: Materially harder than the canonical seed on two independent axes the seed data actually simulates. (1) Contested corridors: churn is enabled (churnSwapNetBenefitThreshold = 2, live; the canonical seed omits the rotation block and so churn is inert), and the rival roster is the tight southern-belt set (MC + GTW LARGE, GR&I + PM MEDIUM, DT&I + Ann Arbor SMALL) all fighting over the same Detroit-Chicago belt, Toledo funnel and Saginaw-Flint throat — freight you hold can be taken when a dearer offer arrives. (2) Dynamic seasonal demand: the rotation block is enabled — a secular auto ramp (+9%/yr on automobiles & auto-parts) plus five calendar-locked seasonal peaks (fall grain/beet/cereal/ furniture and a Jan-Feb lake-ice throat) mean the profitable move changes across the year and the best offers arrive blocked behind cheaper held contracts. A same-tick human can seize a crossover window a delegated manager misses; that gradient is the whole point of the seed. Static territory-picking gets you nowhere here — you must actively re-fight for freight as the seasons turn.

Tooltip-worthy period detail (optional):

The winter lake-ice corridor is real history, not invention: natural ice, cut off frozen rivers at 12-14 inches thick in January-February, was a top-five freight category on the Ann Arbor Railroad (~4%), and the Michigan Central iced its refrigerator cars from Huron River ice at Ypsilanti's "Shanghai Pit." It is a declining trade in the seed (mechanical refrigeration was displacing it through the 1920s) — authentic for a scenario opening in 1920.

Difficulty framing summary (for the catalog author)¶

Seed	Label	One-line why
`michigan_1920s`	Standard	Real rivals, but static competition and no seasonal demand; pressure is picking growing regions over declining timber/copper.
`michigan_contested_1920s`	Hard	Live corridor churn + dynamic seasonal/secular demand; you must actively re-fight for the same freight as the calendar turns.

If the catalog wants a third tier above these later, "Hard" leaves room — michigan_contested_1920s is hard-among-these-two, not the ceiling of what the engine could throw at a player.

Period sourcing & accuracy notes¶

Confidence labels: [FACT] documented history; [INFERENCE] period-plausible but not specifically attested; [SEED] true-in-the-simulation (grounds the copy in what's actually modeled).

Lumber bust by the 1920s — [FACT] Michigan's white-pine boom peaked in the 1880s-1890s and was effectively over by 1900; the 1920s northern Lower Peninsula was "cut-over" land (a documented term of the era), thinning in population. The copy deliberately does not portray a thriving 1920s logging trade — that is the single biggest anachronism risk for this setting, and the seed correctly decays cut-over counties. (Historian memory: michigan_1920s_commodities.)
Copper Country decline — [FACT] Keweenaw/Houghton copper output peaked around 1916 and declined through the 1920s; the seed's copper_country_declining archetype loses ~3.2%/yr. Copy says "crested and begun its long slide" — accurate for 1920.
Detroit auto boom — [FACT] US automobile production rose from ~2.3M (1920) to 5M+ (1929); Detroit was the fastest-growing large US city of the decade. Seed: boom_industrial_whitehot at +5%/yr, plus the +9%/yr auto secular ramp in the contested seed. [SEED]
The named roads — [FACT] Pere Marquette, Michigan Central (NYC system), Grand Trunk Western (Canadian National), Grand Rapids & Indiana (Pennsylvania system), Ann Arbor, Detroit & Mackinac, and Detroit, Toledo & Ironton (Ford-owned from 1920) were all real, operating Michigan carriers in 1920. All appear in the seeds' rivals.json. DT&I was Ford-owned in this period — the copy's "Henry Ford's Detroit, Toledo & Ironton" is literal fact.
Battle Creek cereal / Kalamazoo paper / Grand Rapids furniture / Saginaw sugar & salt — [FACT] All are genuine, era-correct, city-specific Michigan freight origins (Kellogg & Post at Battle Creek; Kalamazoo a top-tier US paper city; Grand Rapids the "Furniture City"; Saginaw Valley sugar-beet and salt/ foundry district). Each is modeled as a corridor in the contested seed. [SEED]
Winter lake-ice corridor — [FACT] Natural ice cut at 12-14" thickness in deep winter; ~4% of Ann Arbor Railroad freight; Michigan Central iced reefers from Huron River ice at Ypsilanti ("Shanghai Pit"). Declining through the 1920s as mechanical refrigeration spread — so authentic for a 1920 opening, and the seed models it as a declining secular trend (correct). (Historian memory: michigan_1920s_winter_ice_corridor.)
$2,000 start / $10k founding target — [SEED] playerStartingCash and founding.targetCapitalization in michigan_1920s/economy.json. The contested seed ships a deliberately generous playerStartingCash (5,000,000) as a test harness value to isolate the contest property, not a player-facing figure — the copy does not quote it. (Flagged for game-dev: don't surface that number in the catalog as a starting-difficulty cue; it is not the intended play balance.)

Accuracy caveats for the PM¶

The contested seed's cash is not real balance. As above — playerStartingCash = $5,000,000 there is a harness sentinel to measure corridor contest, not a design starting purse. The difficulty copy is framed on competitive/seasonal pressure, which is the honest source of the seed's difficulty, and stays silent on the cash. If the catalog ever wants to show a starting-cash figure per scenario, that value must be sorted out with game-designer first — do not read it off the contested seed.
"83 counties / 140 settlements" is the canonical seed's scope; the contested seed is a denser southern-belt subset. The copy reflects this (Seed 1 says "across all 83 counties"; Seed 2 says "Southern Michigan"). Verify the settlement count if you surface it in a tooltip — it's stated for the canonical seed, and the contested seed's footprint is corridor-focused rather than full-state.
No invention presented as fact. Every named road, city, commodity and figure above is real. The only invented element anywhere is the player's own company name, which is fiction by design (the player's road).