Sword of Feast and Famine vs. Planeswalker

[Fuzzy]

If I attack a Planeswalker (Read: Jace) with a creature equiped with Sword of Feast and Famine I untap my lands or not? If not, WHY?

[cdr]

No. Like all of the Swords, you only get the trigger if it hits a player.

"Whenever equipped creature deals combat damage to a player, that player discards a card and you untap all lands you control."