Crafting System

Convert gameplay materials into permanent on-chain NFTs via blending recipes and upgrades.

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Purpose

The crafting system transforms ephemeral gameplay resources into permanent, tradeable on-chain assets. It exists because:

• Gameplay generates materials that have no value if they remain off-chain
• Crafting creates a meaningful THC sink (economic demand)
• Permanent items create ownership stakes that improve retention
• Blending recipes allow game designers to control item scarcity
• Upgrades create a progressive investment loop

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Design Philosophy

OFF-CHAIN                           ON-CHAIN
(gameplay creates)                  (crafting finalizes)
                                    
⚔️ Win matches                      
   → earn materials                  
   → accumulate resources            
                                    🔨 Craft recipe submitted
                                       → materials + THC consumed
                                       → NFT minted
                                       → asset tradeable

Only the output goes on-chain. The per-match material accumulation, inventory management, and resource tracking are all off-chain. The crafting action — which consumes resources and creates a permanent item — is the economic event that justifies an on-chain transaction.

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Components

┌──────────────────────────────────────────────────────────┐
│                    CRAFTING SYSTEM                        │
│                                                          │
│  ┌──────────────┐  ┌──────────────┐  ┌───────────────┐   │
│  │  Recipes     │  │  Blending    │  │   Upgrades    │   │
│  │              │  │              │  │               │   │
│  │ • input list │  │ • multi-NFT  │  │ • level up    │   │
│  │ • THC cost   │  │   combine    │  │ • stat boost  │   │
│  │ • output NFT │  │ • rarity     │  │ • evolution   │   │
│  │ • success %  │  │   upgrade    │  │ • THC cost    │   │
│  └──────────────┘  └──────────────┘  └───────────────┘   │
│                                                          │
└──────────────────────────────────────────────────────────┘

---

Recipes

A recipe defines:

Field	Type	Description
recipe_id	uint256	Unique recipe identifier
inputs	Material[]	Required materials and quantities
thc_cost	uint256	THC consumed on craft
output	NFT definition	What is minted on success
success_rate	uint8 (0-100)	Probability of success (100 = guaranteed)
cooldown	uint256	Minimum time between crafts (optional)
active	bool	Whether this recipe is currently usable

Example Recipes

[
  {
    recipe_id: 1,
    name: "Smoke Blade",
    inputs: [
      { material: "shadow_ore", quantity: 5 },
      { material: "fire_essence", quantity: 3 }
    ],
    thc_cost: 500,
    output: {
      collection: "weapons",
      template: "smoke_blade",
      rarity: "rare"
    },
    success_rate: 100,
    cooldown: 0
  },
  {
    recipe_id: 2,
    name: "Legendary Smoke Blade",
    inputs: [
      { material: "smoke_blade_nft", quantity: 1 },  // NFT input
      { material: "dragon_scale", quantity: 10 },
      { material: "ancient_crystal", quantity: 1 }
    ],
    thc_cost: 5000,
    output: {
      collection: "weapons",
      template: "legendary_smoke_blade",
      rarity: "legendary"
    },
    success_rate: 50,     // 50% chance
    cooldown: 86400       // 24 hour cooldown on retry
  }
]

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Blending

Blending combines multiple existing NFTs into a new, higher-tier NFT.

Flow

Player holds NFT A + NFT B + NFT C
       │
       ▼
Player submits blend request
       │
       ▼
Server verifies:
  • player owns all input NFTs
  • recipe exists and is active
  • player has enough THC
       │
       ▼
Input NFTs burned (or locked)
THC deducted
       │
       ▼
If success_rate check passes:
  → Output NFT minted to player
       │
If success_rate check fails:
  → Inputs consumed (no output)
  → Optional: partial refund or consolation item

Blend Types

Type	Inputs	Output
Same-type fusion	3x Common Card	1x Uncommon Card
Cross-type fusion	Weapon + Armor	Enhanced Set Piece
Material + NFT	NFT + Materials	Upgraded NFT
Sacrifice blend	5x Any NFT	Random higher-rarity NFT

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Upgrades

Upgrades improve an existing NFT's attributes without changing its identity.

Flow

Player owns NFT (Level 1)
       │
       ▼
Player submits upgrade request:
  - target NFT
  - upgrade type (e.g., "attack_boost")
  - materials + THC payment
       │
       ▼
Contract verifies ownership and requirements
       │
       ▼
Materials consumed, THC deducted
       │
       ▼
NFT metadata updated:
  - level: 1 → 2
  - attack: 85 → 95
  - upgrade_count: 0 → 1

Upgrade Limits

Parameter	Purpose	Example
max_level	Cap on total upgrades	10
cost_scaling	How THC cost increases per level	1.5x per level
material_scaling	How material requirements increase	+2 per level
cooldown_per_level	Wait time between upgrades at higher levels	1 hour × level

Cost Scaling Example

Level	THC Cost	Materials Required
1→2	100	2 shadow_ore
2→3	150	4 shadow_ore
3→4	225	6 shadow_ore + 1 fire_ess
4→5	337	8 shadow_ore + 2 fire_ess
...	1.5x	+2 per level

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On-Chain vs Off-Chain Split

Component	Location	Reason
Material accumulation	Off-chain	High frequency, no economic finality
Inventory management	Off-chain	Game state, updated per match
Recipe definitions	Off-chain	Game design data, frequently tuned
Craft/blend execution	On-chain	THC consumed, NFT minted — economic event
Upgrade execution	On-chain	THC consumed, metadata changed — economic event
Failed crafts	On-chain	THC still consumed, must be recorded

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Contract Interface

interface ICrafting {
    // Craft an item from materials + THC
    function craft(
        uint256 recipeId,
        uint256[] calldata inputTokenIds,   // NFT inputs (if any)
        uint256 nonce,
        bytes calldata serverSignature       // server attests material balance
    ) external returns (uint256 outputTokenId);
    
    // Upgrade an existing NFT
    function upgrade(
        uint256 tokenId,
        uint256 upgradeTypeId,
        uint256 nonce,
        bytes calldata serverSignature
    ) external returns (bool success);
    
    // Blend multiple NFTs
    function blend(
        uint256 recipeId,
        uint256[] calldata inputTokenIds,
        uint256 nonce,
        bytes calldata serverSignature
    ) external returns (uint256 outputTokenId);
    
    // View
    function getRecipe(uint256 recipeId) external view returns (Recipe memory);
    function getUpgradeHistory(uint256 tokenId) external view returns (Upgrade[] memory);
}

Why server signatures? The server tracks off-chain materials. The contract cannot verify material balances directly. The server's signature attests that the player holds sufficient materials, and the contract trusts the authorized server key.

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THC Sink Analysis

Crafting is a primary THC sink in the Monsuta Core economy:

Action	THC Consumed	Frequency	Aggregate Impact
Basic crafting	100–500	Several/day	Medium
Legendary crafting	1000–5000	Weekly	High
Upgrades (low)	50–200	Daily	Medium
Upgrades (high)	500–2000	Weekly	High
Failed crafts	Full cost	Per attempt	Acts as extra sink

The game designer controls inflation by tuning:

• Recipe THC costs
• Success rates (lower rate = more THC consumed per output)
• Upgrade cost scaling

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Integration Guide for Other Games

Step 1: Define Your Crafting Economy

• What materials does your game produce?
• What items can players craft?
• What is the currency cost per craft?
• Do you want probabilistic crafting (success rates)?

Step 2: Design Recipes

• Map inputs (materials, NFTs, currency) to outputs (new NFTs)
• Set THC costs that balance your mint/consumption rate
• Define rarity tiers and upgrade paths

Step 3: Deploy Crafting Contract

• Register recipes on-chain
• Set the authorized server key
• Connect to your ERC-20 token contract for THC deduction
• Connect to your ERC-721/1155 contract for NFT minting

Step 4: Integrate with Game Server

• Track material accumulation off-chain
• Generate server signatures when crafting criteria are met
• Either: player submits craft tx (player pays gas) or server submits (server pays gas)

Step 5: Balance and Iterate

• Monitor THC consumption rates from crafting
• Adjust recipe costs and success rates
• Introduce new recipes each season to maintain sink demand