Thanks to Stephen Vann for writing this up.
What constitutes performing an action? What does it mean that my personality can't perform actions?
"Performing" was something that personalities and followers did prior to Ivory Edition. In the beginning of L5R, there was no performing, so everything targeted. To reduce some confusion regarding multiple targets, the terms perform/performer/performing were introduced. These have now been removed. However, some older cards still reference performing. So, follow these guidelines for performing:
-A personality performs any action on his card.
-A follower performs any action on his card.
-A personality performs any action on a spell or item attached to him.
-A personality or follower performs any action that specifically states designates a performer.
-A personality or follower performs any action during which they are targeted "between the colons" and the targeted personality is controlled by you. (for example, old cards had a template such as: Designator:constraints:effect; if the targeting occurs in that "constraints" section, the action is performed by the target)
The first 4 situations should be pretty clear, but that last one can be confusing for players who did not play during the "performing" era. Lets look at some examples:
Doomed Intentions' battle action isn't performed, because the targeting occurs after the 2nd colon:
On the other hand, Cavalry Tactics is performed, because the targeting occurs "between the colons"
Finally, Claw and Shell's battle action isn't performed, because even though the targeting is between the colons, it isn't targeting a personality controlled by you.
Can my guy move to battle using X?
Ivory rules have drastically changed how movement works for older sets, so we use the idea that "movement works as it did when the card was printed." While that sounds complicated, it's really pretty simple. For cards that were printed in Samurai, Celestial, or Emperor editions, "absent," "remote," and "home" didn't exist. So movement cards were given a pass on the rules of presence and location, as long as they "created" presence at the current battlefield. So for cards printed before Ivory Legality, movement is possible even if you don't have presence, as long as at the end of the action, you do. For movement actions on cards in play, the card on which the action appears must be at the current battlefield at the end of the action. Some cards are exceptions to these rules, but they will say so if they are. Currently, a project is underway to update all the old cards to new wording, but until we get there (and probably after), it's just easier to use the "when it was printed" guideline.
What's a reaction?
Reactions are like interrupts, but better. Reactions tell you when to play them. While this can lead to some tricky situations, most of the time the timing is pretty clear. Play them when they tell you to. One other difference that is very important about reactions: they don't require presence or location. You can play reactions at battlefields where you control no personalities.
How does a reaction that says "after engaging" interact with Engage actions?
They are interchangeable. You can play a Reaction to engaging the same time you are allowed to play an Engage action.
How do cards that change deck building interact with Modern deck building rules
Cards that specifically increase or decrease the total number of cards in your deck work as normal. For example Hato-gurama makes your minimum and maximum fate deck size 49 cards. Similarly, Coastal Lane makes your minimum and maximum dynasty deck size 52 cards.
However, cards that change the number of copies of a card you can play will NOT affect deck building. For example, Eternal Victory Dojo will not allow you to play 4 copies of any card, and will not change your minimum or maximum deck size.
If you have any other questions or would like some clarification, please post away!