Smelting survey

Bannerlord v1.5.7 · checked 2026-11-12 · updated 2026-11-12

What smelting each obtainable prebuilt weapon returns per denar spent: material value, iron by grade, part research and Smithing XP, compared against the cheap knives players usually buy to smelt. Numbers are read from game v1.5.7 data and IL.

The full table is research/weapons/smelting.csv, written by scripts/weapons/smelting.py from the formulas in src/bannerlord/crafting/smelting.py and src/bannerlord/weapons/smelting.py. It is not committed; the script regenerates it from the XML and crafting snapshots.

Smelting rules

DefaultSmithingModel and CraftingCampaignBehavior.DoSmelting (IL). No official module (SandBox, StoryMode, NavalDLC, BirthAndDeath) replaces DefaultSmithingModel.

• Smeltable: the smelting screen lists every roster item with IsCraftedWeapon (SmeltingVM.RefreshList), that is with a WeaponDesign, so every prebuilt <CraftedItem>. A throwing weapon is smelted as one item, the whole stack.
• Output: the sum of every piece's Materials. Then the highest grade present among Iron6 down to Iron2 loses one unit and the next lower grade gains one, and one Charcoal is spent (Smithing mechanics).
• Skill XP: round(0.02 × value), rounded half to even.
• Part research: trunc((1 + round(0.02 × value)) × (1 + Curious Smelter)), Curious Smelter adding 1.0. The points go to the smelted item's crafting template (AddResearchPoints(item.WeaponDesign.Template, …)).
• Stamina: trunc(10 × (1 + Practical Smelter)), Practical Smelter adding −0.5.
• value is the base item's value. DoSmelting reads EquipmentElement.Item, so the item modifier (rusty, balanced, …) changes neither output, XP nor research.

Material values are the trade good values in DefaultItems.InitializeAll (IL); no item XML overrides these ids.

Worked example, Broad Bladed Throwing Knives (empire_throwingknife_t5), value 189:

1. dagger_blade_12: Wrought Iron ×1.
2. empire_dagger_guard_3: Iron ×2.
3. empire_grip_2: Steel ×1.
4. empire_pommel_1: Wrought Iron ×1.
5. Sum: Wrought Iron ×2, Iron ×2, Steel ×1.
6. Highest grade present is Steel: one unit drops to Iron, giving Wrought Iron ×2, Iron ×3; one Charcoal is spent.
7. Returned value: 2 × 30 + 3 × 60 = 240.
8. Cost: price 189 + Charcoal 50 = 239; net 240 − 239 = 1; ratio 240 ÷ 239 = 1.004.
9. XP: round(3.78) = 4. Research: 1 + 4 = 5; with Curious Smelter ×2 = 10. Stamina: 10, 5 with Practical Smelter.

Method

Items. Every <CraftedItem> obtainable in campaign, by the Weapon survey rule: sold in shops (merchandise) or carried in a battle equipment set of a campaign character; multiplayer, tournament and tournament-template-only items are excluded. Shop means merchandise; loot only means not merchandise but carried by a campaign character. Value and tier follow Value and price with the v1.5.7 crafting snapshot. Results are given with NavalDLC active and, where they differ, without it.

Price. The item's base value. The town buy price is ceil(value × base × (1 + 0.06 ÷ (1 + 0.002 × Trade))), with the market factor base between 0.8 and 1.3 depending on the town's supply and demand for the item's category (Trade price). That factor is save state, so no single buy price is deterministic. The table gives the bounds for the top items at Trade 0; within one town and category every item scales by the same factor, but the fixed Charcoal cost does not.

Metrics. Cost = price + the Charcoal's value.

• Returned value: units × material value, summed over the output.
• Net: returned value − cost.
• Ratio: returned value ÷ cost.
• Units per 1000 denars: units of one iron grade × 1000 ÷ cost.
• Research and XP per 1000 denars: per smelt, × 1000 ÷ cost. Per stamina: ÷ the stamina of one smelt with no perk.

Material values are base values; the markets trade materials at a factor of 0.1 to 10 of them, so the ratio measures yield, not profit at a given town.

Material value

Top items by ratio with NavalDLC:

• Within 10% of the best ratio (≥ 0.904): Broad Bladed Throwing Knives (empire_throwingknife_t5) 1.004.
• Next best: Highland Throwing Dagger (celtic_throwing_dagger) 0.800, 79.7% of the best.

Every obtainable knife (templates Dagger and ThrowingKnife), by ratio rank with NavalDLC:

Without NavalDLC:

Iron by grade

The three best sources per grade by units per 1000 denars, with the best knife for the grade. With NavalDLC:

Without NavalDLC:

Research and XP

Research and XP per smelt depend only on value. The table gives the curve; the rounding of 0.02 × value makes some values return more per denar than their neighbours. Above a few hundred denars, research and XP per denar settle at 0.02 minus the Charcoal's share. Per stamina both grow with value, so a stamina-limited smith smelts the most valuable items they can afford.

Stamina per smelt: 10, 5 with Practical Smelter.

Research per 1000 denars, top items with NavalDLC:

• Range of research per 1000 denars: 21.74 (Short Militia Spear (imperial_spear_t2)) to 16.81 (Wooden Hammer (peasant_hammer_2_t1), value 69).
• Best knife: Broad Bladed Throwing Knives (empire_throwingknife_t5), rank 5, 20.92.

Research goes to the smelted item's template. The best item per template by research per 1000 denars:

XP per 1000 denars, top items with NavalDLC:

• Lowest: Wooden Hammer (peasant_hammer_2_t1), value 69, 8.40 XP per 1000 denars.
• Best knife: Broad Skaen (Broad_Skaen), rank 98, 19.87 XP per 1000 denars.

Game version

v1.4.8 → v1.5.7 IL of GetSmeltingOutputForItem, AddSmeltingReductions, GetSkillXpForSmelting, ResearchPointsNeedForNewPart, DoSmelting, AddResearchPoints and DefaultItems.InitializeAll is unchanged. GetPartResearchGainForSmeltingItem and GetEnergyCostForSmelting now apply their perk through PerkHelper.AddPerkBonusForCharacter instead of Hero.GetPerkValue + AddFactor; Curious Smelter and Practical Smelter have role Personal and increment type AddFactor, and their values are unchanged, so the result is the same. The Native crafting XML changed piece stats of cleaver_blade_3, spear_blade_22, spear_blade_44 and sturgian_noble_blade_3 to _6, which changes the value of items using those pieces; no piece's materials changed.

Open questions

• Whether towns stock iron ingots, and at what factor, is not modelled.
• Item modifiers lower the buy price (price_factor below 1) without changing smelting; how often shops stock such items is not measured.
• None of this has been checked against game output.