Nintendo formally unveiled its new Switch Online service on Thursday, and one of the more notable details was the need to subscribe to the service for multiplayer games. Detailed in one of the FAQs, however, it specifically mentions the super-popular shooter Fortnite as one of the games exempt from the policy, and it implies that there will be others

For instance, Tencent confirmed to Variety that its multiplayer battle title, Arena of Valor, falls under the no-subscription umbrella as well

The FAQ lists Splatoon 2, Mario Kart 8 Deluxe, Arms and SuperBros. Ultimate as games that definitely do require a membership

Membership details from Nintendo's FAQ.Nintendo
Policies on subscription requirements vary across platforms, even for the same game. Fortnite on the PlayStation doesn't require a PS Plus subscription, but on Xbox it does require Xbox Live Gold

We asked Nintendo how it decided when Switch Online membership was required, and the company responded, "Certain games, such as Fortnite, can be played online without a Nintendo Switch Online membership. Various factors could determine if a game requires the service."
The FAQ also notes that sharing screenshots and video over social networks, updates and some other services won't require a membership either

Fortnite is free to play, and sensationally popular with kids, who probably don't haveor dad's credit card at their disposal

Switch Online costs $3.99 3.45, AU$5.95) per month, or $20 18, AU$30) if buy a year's subscription. Here's what you get for your money.