Virtuous actions (positive deeds coming from wholesome intentions) sow seeds of future happiness.
On the other hand, non-virtuous actions (negative deeds arising from unwholesome motivations) sow seeds of future suffering.
These karmic seeds can remain dormant in our mind until the conditions for them to ripen occur – and then they produce their effect.
The ten non-virtuous actions are three actions of the body, four of speech, and three of the mind:
Bodily actions: killing, stealing, sexual misconduct
Verbal actions: lying, slander (divisive speech), harsh speech (hurtful words), and gossip (idle chatter)
Mental actions: covetousness (greed), harmful intent (hatred), and holding wrong views (ignorance)