411 REFERENCE · Wikibooks
Chess Opening Theory/1. e4/1...e5/2. Nc3/2...Nc6/3. f4/3...exf4/4. d4
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
The Steinitz Gambit is a rare, offbeat and dubious sideline.
The move allows Qh4+, which forces Ke2. In return for the embarassed King and the pawn, White will get to develop with tempo and keep an intimidating pawn centre.