When Zhonya's Hourglass is played from hidden, does it only save units at the battlefield where it was hidden, or can it save units anywhere (including base or other battlefields)?

Ruling: When Zhonya's Hourglass is played from hidden at a battlefield, the design intention is that it should only save units at that specific battlefield. However, the current rules do not support this intention, and updated rules are expected to clarify this interaction.

Nuances:

• Rules as written (RAW) would allow Zhonya's to bounce to base immediately and save any friendly unit anywhere, which is not the intended behavior
• The general rule for hidden cards adds implicit "here" targeting to limit effects to the battlefield where they're hidden
• Tournament organizers currently use their own specific interpretations until official clarification
• If played normally as a gear in base (not from hidden), it would save the next friendly unit that would die anywhere, though opponents could force it to trigger on a token