Each Emotion has a power that affects gameplay. Some of these powers are only relevant when the Emotion is put into play, while others have an ongoing ability that triggers in certain situations. The powers of the Emotions are described in detail on the Emotion sheets. When the text refers to you, it assumes that it is currently your turn and the Emotion belongs to your team.
When the text refers to putting an Emotion into play, that means you have just now put it into an Emotion slot on the board. Mild Emotions enter play when they are invoked. Strong Emotions enter play when their Mild counterpart is empowered. As soon as an Emotion enters play it is in play, and it remains in play until it leaves play. Moving an Emotion from one slot to another does not count as entering or leaving play.
When an Emotion receives an Intensity token, that means it gets a bonus to its Intensity beyond the amount printed on the card. The Intensity token affects only the numerical value of the Emotion’s Intensity and has no effect on attempts to intensify, empower, or quell. The Intensity token is discarded if the Emotion card is discarded (for example, because it is empowered or quelled). In most cases, the Emotion receives an Intensity bonus when it enters play, and the bonus remains the same while the Emotion is in play. Some Emotions have bonuses that change dynamically, and these are noted in the text. An Emotion cannot have more than one Intensity token, and the highest Intensity bonus an Emotion can get from a token is 6.