Internet connection required
Diablo IV requires a Battle.net account and an internet connection on every store, including Steam. Offline play is not supported. The Steam free window for the base game runs until September 21, 2026 at 10 a.m. PT and is not a permanent free-to-play change. About 15 percent of Season of Hell's Legacy objectives, including Rank VIII rewards, want Lord of Hatred. Eight classes are playable on live realms after that expansion; Amazon is announced for 2027.
Account and connection rules
Battle.net is the account layer under Steam, consoles, and the Battle.net launcher itself. Internet connection required is the short version of the legal notice: every mode, not only co-op. If someone tells you there is a LAN or offline campaign, they are describing a different Diablo. This one drops you when the connection drops.
China runs a NetEase PC path at d4.blizzard.cn with the official name 《暗黑破坏神IV》. Other markets use Battle.net. Cross-play copy on Steam covers the available platforms in those Battle.net markets. Keep one Battle.net account if you bounce between Steam and a console. Steam's legal notice is the PC wording. Console stores still need Battle.net for cross-play. A dropped connection ends the session in campaign, seasonal, and Eternal alike. There is no offline exception for story-only play. Use Battle.net support for password resets; this site cannot open those tickets.
Buying and season questions
The base game is required for Vessel of Hatred and Lord of Hatred. Lord of Hatred includes Vessel of Hatred. The Age of Hatred Collection includes the base game plus both expansions and is the Switch 2 eShop product. Do not buy Vessel of Hatred again if you already checked out Lord of Hatred.
Season of Hell's Legacy is live on patch 3.2.1. Free play on Steam ends September 21, 2026 at 10 a.m. PT. For class ownership see Diablo IV classes. For SKUs see platforms and editions. For the season systems see Season of Hell's Legacy. Standard is the base game. Vessel of Hatred is Spiritborn and Nahantu. Lord of Hatred includes Vessel of Hatred plus Paladin and Warlock. Age of Hatred Collection is the full stack, including the Switch 2 eShop product. Do not buy Vessel of Hatred again if Lord of Hatred is already in the library.
Why these six questions
These six questions are the account and purchase cluster: Battle.net, offline play, the free window, the Lord of Hatred season gate, cross-play, and the eight-class roster. They are the questions that dump a new player out of Sanctuary before a Helltide. If your question is about Waking Nightmare sizes or jewelry gems, use the season and Soul Splinters ledgers instead.
Internet connection required is the H1 because that is the legal-notice fact people search when a Steam install will not stay at the login screen. Base game required and all 8 classes are the other two phrases this page is built to answer. None of those three is a rumor; they are store and patch facts. Internet connection required, base game required, and all 8 classes are the three phrases this FAQ owns. Everything else on the site is a season, class, SKU, or activity ledger linked from the related list below.
Where to go after the FAQ
If the answer was Battle.net or offline play, you are done: sign in and stay online. If the answer was the free window, set a reminder for September 21, 2026 at 10 a.m. PT and follow Getting started. If the answer was Lord of Hatred for Rank VIII, open that expansion page before you buy a second DLC you already included.
If the answer was eight classes, open the class roster and filter by the expansion you own. If the answer was cross-play, keep Battle.net on every store and ignore expansion gates at your own time. The FAQ does not replace the season ledger or the SKU table; it only clears the account questions that block those pages. Getting started is the install order. Platforms and editions is the SKU order. Season of Hell's Legacy is the anniversary systems. Classes is the eight-row roster. Use those four links instead of rereading the same account rules.
Frequently asked questions
Do I need a Battle.net account on Steam?
Yes. Steam's legal notice and external account notice require a Battle.net account and an internet connection for all modes. Buying the Steam SKU installs the Windows client, then you sign in to Battle.net. There is no Steam-only offline profile. Console stores use the same Battle.net requirement for cross-play and cross-progression.
Can I play offline?
No. An internet connection is required. The Steam legal notice states that requirement for every mode, not only multiplayer. If your connection drops, you leave the session. This is the always-online rule behind the page title Internet connection required, and it does not change during the Steam free window.
Is Diablo IV free right now?
Steam is running a free-play window for the base game until September 21, 2026 at 10 a.m. PT, with all classes and leveling to 30. The store still marks the game as not permanently free. After that timestamp you buy Standard, an expansion, or the Age of Hatred Collection if you want to keep playing. The window is a timed promotion, not a free-to-play relaunch.
Do I need Lord of Hatred for Season 15?
The season runs for all players. Official notes say about 15 percent of seasonal objectives, including Rank VIII rewards, require Lord of Hatred. War Plans and several expansion loops sit behind that SKU. You can still run Waking Nightmares, socket Soul Splinters, and play base-game endgame without Lord of Hatred. Buy it if you want the full rank track.
Is there cross-play?
Yes. Steam copy states cross-play and cross-progression on all available platforms. Sign in with Battle.net on each store, keep an internet connection, and group across PC and console. Cross-play does not remove expansion gates: a Spiritborn still needs Vessel of Hatred, and Paladin or Warlock still need Lord of Hatred.
How many classes are playable?
Eight on live realms after Lord of Hatred: Barbarian, Sorcerer, Druid, Rogue, Necromancer, Spiritborn, Paladin, and Warlock. The Steam base store page still says five; expansion SKUs and patch notes name all eight. Amazon is announced for 2027 as a class pack and is not playable in Season of Hell's Legacy. The base game is required for every expansion class.