> [!CAUTION]
> **Caution:** This documentation is for Google Ads API **v24** . The latest active version is [**v26**](https://developers.google.com/google-ads/api/reference/rpc/latest/ExperimentArm.ExperimentalPerformanceMaxCampaignSettings).

Parameters for an experiment to create a Performance Max campaign. The experimental Performance Max campaign gets created automatically based on the existing SHOPPING campaign settings and the settings specified in this field.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v24/resources/experiment_arm.proto)

| Fields ||
|---|---|
| ## `bidding_strategy_type` | `BiddingStrategyType` Immutable. Bidding strategy type of the Performance Max experiment campaign. |
| ## `budget_amount_micros` | `int64` Immutable. The amount of budget of the Performance Max experiment campaign. |
| ## `target_cpa_micros` | `int64` Immutable. Target CPA of the Performance Max experiment campaign. |
| ## `target_roas` | `double` Immutable. Target ROAS of the Performance Max experiment campaign. |