Apple’s own support page confirms new subscribers can “choose the trial subscription offer” when joining Apple Arcade, with one trial available per Apple Account.

Open the App Store, go to the Arcade tab and follow the prompts to start your free trial – a payment method is required to activate it, and the full library of 200+ games with no ads and no extra in-app purchases is unlocked immediately.

Cancel via Settings > your name > Subscriptions before the trial ends to avoid being charged the standard monthly Apple Arcade fee once it converts to a paid subscription.