Competing Solutions - Heliomance/Uncharted-Horizons GitHub Wiki

_{Discovery Mechanics · Design document §1.2}

Some goals can be reached in more than one way — furnaces hot enough for steel, power beyond a basic fission plant — and one way is usually easier or better, so most civilisations find it first and never bother with the other. The road less travelled is uncommon because it is pre-empted, not because it is hard. A Competing Solutions group models this: one goal, a primary solution and one or more alternatives.

• Alternatives carry a normal tier (usually STANDARD), so once a civilisation is on the trail it does not elude them.
• A detour margin — a cost multiplier on the alternative's price, ×1.5 to start — tunes the race: a civilisation pursuing both usually finds the primary first. Prerequisites shape the race too, so a civilisation that cannot reach the primary yet is already on the alternative's trail, and its study goes on every turn it stays stuck.
• Lock-out is one-way. Discover the primary first and the alternative is never developed (a Path Not Taken, §1.4). Discover the alternative first and the primary still arrives later, with one of two outcomes set per group: the alternative is superseded when the primary is better in every circumstance (its objects carry Unavailable <after discovering [primary]>, its units take the primary as obsoleteTech, its bonuses <before discovering [primary]>), or it persists when it keeps a lasting advantage — independence from a scarce resource, a capability the primary lacks, or a chain of its own. A persisting alternative can send a civilisation down a whole different road simply because it found things in a different order: the deep fission chain is the model case.
• A persisting alternative trades; it never simply adds. The conventional route usually wins for a reason, so an alternative carries real disadvantages as well as real advantages, and it competes for the primary's slot — a mutually exclusive building, the same understanding token, a bonus that does not stack. A civilisation holding both then has a choice in each city, not an accumulation: the order it found things changes its options, never its total.
• When the primary cannot exist in this world — removed by a Removal Truth, foreclosed by a foundational axis, or dead-ended by a frontier axis — the World-Truth ruleset derivation drops the margin and gives the alternative the primary's tier. It can never be locked out; it is simply the way.
• Grand Endeavours suspend lock-out (§1.5), so a civilisation can take the road less travelled on purpose.
• A second kind of road not taken is lost confidence rather than pre-emption: the airship chain is not superseded by aeroplanes, but each Airship Disaster lowers the tier of its undiscovered breakthroughs, for the sufferer and, by report, for its neighbours (below).
• Lock-out is always per civilisation, never global. Only alternatives in a Competing Solutions group can ever be locked out. The groups are listed in §6.

The rigid airship was not pre-empted; it was abandoned, one catastrophe at a time. The Airship Disaster models that as a second kind of road not taken — lost confidence, beside the pre-emption of Competing Solutions (above).

• The risk. Every gas airship — the Airship, Rigid Airship and Sky Fortress, but never the hot-air Observation Balloon — carries ⟨Triggers a [Airship Disaster] event <with [1]% chance> <upon turn start> <before discovering [Helium Extraction]>⟩. Exposure scales with investment: a lone scout rarely burns (about a 40% chance over fifty turns); a fleet of five almost surely will.
• The disaster. The Airship Disaster event (Events.json, a popup for the player, automatic for the AI) destroys the airship that rolled it — Unciv passes the triggering unit into the event, so its effect is ⟨[This Unit] is destroyed⟩ — and applies the confidence shock below.
• The confidence ladder. Each civilisation's undiscovered breakthroughs of the airship chain (AE02, AE13, AE12) stand at STANDARD, UNCOMMON or RARE. A civilisation that suffers a disaster drops straight to RARE. Every major civilisation in contact with it receives the Airship Disaster Report event and drops one step — so a first report means UNCOMMON, and a second, from any source, RARE. A civilisation that holds Helium Extraction is unshaken by reports. Confidence never recovers; a Grand Endeavour can still push a civilisation on.
• The dynamic. Prevalence of airships depends on whether a civilisation has sunk enough into them — or found helium — before disaster strikes, at home or abroad. Helium Extraction is UNCOMMON (v3.124), as helium was long one nation's near-monopoly, so for most civilisations the airship's story ends in disaster, as it did in ours.

The risk and the destruction are native. The ladder and the broadcast to contacted civilisations are fork code, since tiers belong to the fork's discovery system and Unciv has no way for one civilisation's event to reach another.

Every group, with its primary, its alternative and what happens if the primary arrives later: Competing Solutions Reference (§6).