A few people have expressed some confusion over what constitutes an ability use.
To use an ability, simply send me a PM. If your targets are valid, your ability is not on cooldown, and you have uses remaining, you will attempt to use that ability. You cannot use the same ability more than once per round (even in the case of #U abilities), but you can use more than one ability on the same night, if you have multiple. Because passives can never be manually activated, they can also never be used (for the purpose of abilities that check whether an ability was activated) and cannot be disabled, except by your death. If you fail to use your ability (most commonly because of Time Fracture or Consecrate Ground), it will be treated as though you simply did not activate your ability. If you send me an invalid command, like targeting yourself with an ability that cannot do so, I will tell you this, but if you do not update your action it will be treated as though you did not activate your ability.
Rose Petals is a special case. If all conditions for Rose Petals are met, and your ability has a lower priority than Rose Petals, you will be compelled to use your abilities on Rita, regardless of any instructions you may have provided. Note that in very rare circumstances, this may cause abilities to fail when they otherwise would not. (For example, if Rita is affected by Consecrate Ground but your original target was not, you will receive the message for being compelled by Rose Petals, as well as the message for your ability failing, and your ability use will be refunded as if you simply did not activate your ability.) Keep in mind that Rose Petals only checks to see if the ability can target one player, not whether it currently is, so it will affect abilities that target "up to three" players, or "any number of players" in the case of Radio Wave.
The rulings section has been updated.