Gainer

A "Gainer" is any card which allows you to gain cards without using buys. The most basic example is workshop. Most of these cards are action cards and trigger on the action phase. However, Horn of Plenty and Hoard are treasures and trigger on the buy phase. Almost all of these cards work well with the cost-reduction from Highway and Bridge. These also mostly work with Gardens strategies as they allow you to gain more cards than you have buys. The only exceptions to this rule are cards such as Remodel which require a card to be trashed in order to gain a new card