The following adds to the skill cards used in the base game. There are five new cards (five in number, one of value 5, 4, 3, 2, 1) for every old skill (Engineering, Piloting, Politics, Tactics, Leadership). These are as follows.
Value 1-3: Jury Rigged LEADERSHIP
Play before cards are added to a skill check to reduce difficulty by 4. This card is 'Reckless', I'll explain it later.
Value 4-5: Calculations
Play after a die is rolled to subtract or add 1 to the result. Only one Calculations card per check.
Value 1-3: Major VictoryPILOTING
Play after you destroy a basestar or a centurion on the boarding track to roll a die. If 5 or higher, gain 1 morale. Only one Major Victory card per turn.
Value 4-5: At Any Cost
Play before cards are added to a skill check. All Treachery cards count positive for this check. Reckless
1-3: Full ThrottlePOLITICS
Movement or Action: If piloting a Viper you may move to any space area. You may then attack 1 cylon ship in the area (even if you didn't move). Explanation: From what I can see, this card can be used as a "movement action", in that you can use your Movement phase to play it instead. Some Cylon abilities have this as well.
4-5: Run Interference
Play before cylon raiders are activated. The first 4 raiders activating in your space area automatically miss (they do not roll attacks).
1-3: Support the PeopleTACTICS
Play before cards are added to a skill check. Each human player with 4 or less skill cards in hand may draw 2 skill cards. Reckless
4-5: Preventative Policy
Movement action: Choose 1 resource type, the next loss of this resource during this turn is reduced by 1.
Note: in Pegasus, Investigative Committee does not apply to cards from the Destiny Deck; they remain hidden even when playing IC on a check.
1-3: Guts and Initiative
Play before cards are added to a skill check. Do not add cards from the Destiny Card to this skill check. Reckless
4-5: Critical Situation
Movement action: Take 1 Action. Only 1 "Critical Situation" or "Executive Order" card may be used per turn (i.e. if you played one, you can't play the other one).
Treachery is a new type of skill card. You do not usually draw Treachery on your own volition, though some characters like Cylon Leaders and Ellen do. They count against a skill check most of the time. The notable exception is Execution, which we'll get to later. But it's basically airlocking people! Fun.
Treachery cards relate to the reckless quality mentioned. If you play a skill card as an action (i.e. the printed ability on the card, not as a regular card) and the action includes "Reckless", this renders the skill check Reckless. Only one such card may be played per skill check.
This is significant for several Treachery cards. If a Treachery card with a "Reckless Skill Check" trigger is revealed in a Reckless skill check (as in, they need not be played as an action, they simply need to be in the stack), bad things will happen. What, is printed on the card. So to reiterate, checks are rendered Reckless by the specific play of a printed ability, and this may trigger Treachery cards that have been played into the skill check stack.
Two Treachery cards will be included in each Destiny Deck.
Broadcast Location (value 1 only, 8 in the deck)
Reckless Skill Check: Place 1 basestar in front of Galactica and 1 civilian ship behind. Only 1 of this ability may be resolved in each skill check. (I.e. you will not get hit with two basestars by two of these cards in one reckless skill check.)
By Your Command (Value 1 only, 4 in the deck)
Reckless Skill Check: Activate all raiders, heavy raiders and occupation forces* (but not centurions). Only 1 of this ability, etc.
God's Plan (Value 2 only, three)
Movement action: Exchange this card with the top card of the Destiny Deck.
Special Destiny (value 2, five)
Reckless Skill Check: Each player draws 1 Treachery card. Only 1 of this ability, etc.
Human Weakness (value 3, two)
Action: If at least one human player is in the Brig or Detention*, reduce the highest resource by 1.
Sabotage (value 3, four)
Play when a human player discards a Treachery skill card. Damage Galactica. Only 1 Sabotage card may be used per turn.
* New Caprica phase stuff. I'll get to it.
So yes, you can discard Treachery cards if you need to discard cards from crisis cards etc., or if you are over your limit, but there are risks.