Stampede is an Event from that allows you to gain 5 s directly onto your deck, but only if you can get without playing more than 5 cards. This effectively doubles the size of your next hand, since once you play all five Horses, you'll have 10 cards.
 Official FAQ
- It does not matter how many cards you played that turn, only how many you have in play when buying Stampede. If there are fewer than 5 Horses left in the pile, just gain as many as you can.
 English versions
|| If you have 5 or fewer cards in play, gain 5 Horses onto your deck.
|| March 2020
 Other language versions
|| Falls du 5 oder weniger Karten im Spiel hast,
nimm 5 Pferde auf deinen Nachziehstapel.
Sadly the art doesn't show 5 horses.
 Secret History
The initial idea was to reward you for not having very many cards in play; it started as "if you have 3 or fewer cards in play, gain 5 ." It wasn't getting used much; so, it's more generous on the situationalness and puts the onto your deck.