Resource Parity

Makes the total amount of each map resource the same on every map, regardless of the Colony Site's resource level. In vanilla a low-resource site gives fewer and leaner deposits and a high-resource site more and richer ones (the per-level numbers are on the Colony Sites page); this pins every map's totals to a fixed target while leaving the number of spots exactly as vanilla rolled them - only the amount each spot holds changes. Status: Tested v2.9 - in StS as Code/StS_ResourceParity.lua.

Targets

Every map is normalized to these totals (the numbers a deposit's tooltip shows). "Surface and shallow" is the tier workable with no deep tech (surface piles plus depth-1 scanned deposits); "deep" is the depth-2 tier behind Deep Water Extraction / Deep Metal Extraction. Metals surface splits into the loose piles you pick up directly and the depth-1 scanned metal. These are the rough baseline; Metals and Rare Metals are then shifted by map Topography (see below), Water and Concrete are not.

Resource	Surface and shallow	Deep
	50k	150k
	20k	none
	7.6k = 1200 loose piles + 6.4k shallow scanned	13k
	3k	5k

So at the rough baseline total Metals on a map is 20.6k (1.2k + 6.4k + 13k), total Water 200k, total Rare Metals 8k, total Concrete 20k. The spot counts stay whatever the generator rolled, and the deposit grade (the 60-140% roll) is left vanilla: grade is a mining-speed modifier, not stored amount, so it changes nothing here.

Topography shifts Metal and Rare Metal

The hillier the map, the more Metal and Rare Metal it carries. Every Metals and Rare Metals target above (loose, shallow, deep) is scaled by (100 + pct)/100, where the percent comes from map Topography (StS_TopographyMetalPercent in Code/StS_ConditionTopography.lua). Water and Concrete are untouched.

Two mechanisms

Concrete has to be handled differently from the other three, so the feature has two parts.

Concrete - scaled before generation (exact on average)

Terrain concrete is a painted terrain patch, and the extractor physically digs that patch. Its minable amount is Min(painted-terrain yield, max_amount) (TerrainDeposit.lua:551), so raising max_amount after the map is built cannot conjure more concrete - the terrain area caps it. Concrete therefore has to be scaled at the ResourcePreset before the map builds, which scales the painted terrain and the amount together.

On ClassesBuilt the mod scales the three per-patch volume ranges (TerrSizeVol1/2/3) on Concrete_VeryLow .. Concrete_VeryHigh so each level's expected total is 20k, leaving the patch counts (TerrSizeCount1/2/3) untouched. Because concrete is many small-to-large patches, the per-map roll around 20k is modest - concrete is exact on average, not identical every map. (This is the same preset edit the ConcreteTriple probe proved.)

Water, Metals, Rare Metals - normalized after generation (exact)

These three are scaled from the actual deposits the generator placed, so the total is exact on every single map - not just on average, and not dependent on the site level. That matters most for the deep tiers, which spawn few spots with a wide count roll (deep water 2-6 spots, deep metal 4-10): a preset-only scale would leave a big per-map wobble there, and reading the real map removes it.

• Hook. Msg("MapSectorsReady", exploration) fires at the end of Exploration:Init (Exploration.lua:1139), after every deposit marker is registered. The mod runs once per colony (guarded by a saved flag) and only on the main Mars map; Below and Beyond asteroid / underground maps are created later by player action, use their own *_Asteroid_* / *_Underground_* presets, and are left alone.
• Tier buckets. The game already splits markers by tier into sector.markers.surface / .subsurface / .deep (GetDepositList → GetDepthClass, Exploration.lua:371-375; SubsurfaceDeposit.lua:55-57). Surface holds the loose metal piles (and concrete, skipped here); subsurface is depth-1; deep is depth-2.
• Scaling. For each (tier, resource) the mod sums the placed amounts and multiplies every deposit by target / actual, so the sum lands exactly on target while the spots keep their relative sizes. Editing an unrevealed marker's max_amount carries into the deposit the player later scans: both SubsurfaceDepositMarker:SpawnDeposit and SurfaceDepositMarker:SpawnDeposit build the deposit with max_amount = self.max_amount (SubsurfaceDeposit.lua:85-86, SurfaceDeposit.lua:91). An already-placed deposit is updated in place as well.
• Loose metal piles are the exception. A surface-metal marker's max_amount is 0; the 5-15 per-pile amount is rolled at spawn (SurfaceDeposit.lua:43,51-55,139-142), so a ratio scale means nothing. Instead every loose-metal marker is set to a flat target / N (N = number of loose-metal spots on the map; target 1200 at the rough baseline, shifted by topography), which is exact and applies to piles spawned later on scan; any pile already placed is updated via SurfaceDeposit:Setmax_amount, which also updates its drone request (SurfaceDeposit.lua:202-206).

Scope

Affects new colonies only - deposits on an existing save were already rolled at generation time and are not touched. Spot counts are never changed; only per-spot amounts. Amounts are stored internally as the on-screen number × const.ResourceScale (1000), the same convention the other rebalances use.

Sources

Base game and DLC, decompiled (method: docs/reading-surviving-mars-code.md). The per-level vanilla resource totals this normalizes are derived on the Colony Sites page.