Rule Exclusivity & Stacking
PredictCart provides fine-grained control over how multiple rules interact when they all match a cart item or the cart.
Per-Rule Exclusivity
Each rule has an exclusivity setting that determines its behavior relative to other matching rules:
| Exclusivity | Behavior |
|---|---|
| Individual | The rule applies independently and can stack with other individual rules |
| Cannot combine | This rule cannot combine with other rules; other rules are skipped when this one matches |
| Only this | When this rule matches, all other rules are stopped |
| Disabled | The rule is inactive |
Global Selection Method
For Product Pricing rules, a site-wide setting determines how matching rules are selected:
| Method | Behavior |
|---|---|
| Apply all | Apply every matching rule (respecting exclusivity) |
| First matching (default) | Only the first matching rule (by priority order) is applied |
| Best price | The rule producing the lowest price is selected |
| Biggest discount % | The rule with the highest percentage discount is selected |
| Highest price | The rule with the highest resulting price is selected |
| Best (legacy) | Uses the legacy estimator to find the best combination |
Stacking Behavior
When multiple rules with Individual exclusivity match the same cart item, their discounts stack:
- Each rule is applied sequentially to the current price
- Stacking respects the global stacking cap (max rules, configurable in settings)
- Total discount cannot exceed the item's line subtotal