you´ll find special rules for the feat cards on page 5 of the toi-rulebook:
"During setup, after the Skill cards have been dealt to the hero players, separate the three Feat decks (fighting, subterfuge, and wizardry) and shuffle them individually. Then, each hero player draws the quantity and selection of Feat cards indicated by the starting skills section of his hero sheet."
Playing Feat Cards
"Each Feat card lists one or more triggering conditions that determine the timing and situation in which it can be played. Hero players may play Feat cards at any time as long as the triggering conditions have been met. After playing a Feat card, the hero player simply follows the instructions printed on the card, resolves its effects, and discards the card onto a discard pile for that feat type.
Important: Each hero player may only play one Feat card per turn. So, for example, each hero player may play one Feat card on his turn, and one Feat card on the overlord’s turn."
Drawing Feat Cards
"When a hero player activates a glyph, all hero players may draw one Feat card (unless their hero sheets state differently). Additionally, some quests’ treasure chests yield Feat cards as rewards. When a treasure chest lists a Feat card as a reward, all hero players may draw one Feat card (unless their hero sheets state differently).
When several players must draw Feat cards at the same time, they may decide among themselves what order to draw them in. If the hero players cannot agree, the overlord player chooses for them.
Each hero player may only draw from Feat decks of the types they are able to draw from during setup.
When a hero player draws the last card in a Feat deck, the hero player shuffles all the discarded cards of that feat type and creates a new deck.
If a Feat card deck runs out of cards and there are no discarded cards of that feat type, the hero players cannot draw that type of Feat card, and must draw another Feat card type, if able.
Unless otherwise stated on a player’s hero sheet, a player’s maximum Feat card hand size is four. If a player already has four Feat cards in his hand, he may still draw Feat cards when able, but then must immediately discard back down to four."
if some of the cards require special rules or are exchanged, they come with the rtl or you find an explanation in the rtl rulebook.