Shopify Collection Rules Engine: Understanding Automated Logic

Shopify's collection rules engine powers automated collections by evaluating products against conditions you define. This guide explains how the rules engine works and how to use it effectively.

How the Rules Engine Works

The rules engine operates through a simple process:

• You define conditions for product inclusion
• The engine evaluates each product against these conditions
• Matching products are automatically added to the collection
• Products are re-evaluated when their attributes change

Rule Components

Attributes

Product data that can be evaluated:

• Product title
• Product type
• Vendor
• Product tag
• Price / Compare at price
• Inventory stock
• Weight
• Variant title

Operators

How values are compared:

• Equals: Exact match required
• Not equals: Excludes matching values
• Contains: Partial text match
• Starts with / Ends with: Position-based text match
• Greater than / Less than: Numeric comparisons

Values

The target data to match against:

• Text strings for title, type, vendor, tag
• Numbers for price, inventory, weight

Logic Operations

AND Logic (All Conditions)

Select "Products must match all conditions" — products must satisfy every rule to be included:

• Creates precise, targeted collections
• Example: Type = "Shirts" AND Price > 50 — only shirts above $50 appear
• Each additional AND condition narrows the results further

OR Logic (Any Condition)

Select "Products must match any condition" — products matching at least one rule are included:

• Creates broader collections
• Example: Tag = "featured" OR Tag = "popular" — products with either tag appear
• Each additional OR condition expands the results

Limitation: Shopify doesn't support mixing AND and OR logic in a single collection — you cannot create "Type = Shoes AND (Tag = red OR Tag = blue)" natively. Workarounds include using combined tags (e.g., shoes_red, shoes_blue) or third-party apps like AWSM Collections that support grouped conditions.

Rule Evaluation Timing

The rules engine evaluates products:

• When a new product is created
• When product attributes are updated
• When collection rules are modified
• When products are imported via CSV

Designing Effective Rules

• Start with simple, clear conditions
• Use consistent product data for reliable matching
• Test rules with known products
• Avoid overly complex rule combinations
• Document your rule logic for team reference

Common Rule Patterns

• Sale items: Compare at price > 0
• In stock: Inventory stock > 0
• Brand pages: Vendor = "Brand Name"
• Category pages: Product type = "Category"
• Tagged items: Tag = "specific-tag"

Troubleshooting Rules

• Products not appearing: Check attribute values match exactly
• Too many products: Use AND logic with more conditions
• Unexpected products: Review OR vs AND logic

Conclusion

Understanding Shopify's collection rules engine helps you create more effective automated collections. Focus on clear conditions, consistent product data, and simple rule structures for reliable automation.

Related Resources

• Shopify Help: Collections
• What is a Shopify Collection?
• Using Tags Effectively