A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
A player, 27 January 2012
Definition of effect
An effect is anything, other than a cost, that creates a card or other thing in the game, changes the characteristics or state of a card, stat or other thing in the game, adds restrictions or permissions to the game’s procedures, or creates a new instance of a game procedure
Bad Kharma
Reaction: After another player with Family Honor of -1 or lower announces an action on a Strategy: He ignores the action's costs. Negate its effects.
If he announces a reaction like iron will or another bad kharma, and I try to bad kharma it. Is "ignore costs" and "negate effects" technically an effect? It doesn't change any numbers or stats nor does it create a card or other thing. It doesn't add a restriction or permission to the procedure. Iron will creates an additional action, which is obviously negated. I guess it removes an instance of game procedure (paying costs), but that example isn't given. But I can't tell if 'negating' actually falls under the above definition of an effect.
Brook Cunningham (rules official), 7 February 2012
Definition of effect
Bad Kharma
If he announces a reaction like iron will or another bad kharma, and I try to bad kharma it. Is "ignore costs" and "negate effects" technically an effect? It doesn't change any numbers or stats nor does it create a card or other thing. It doesn't add a restriction or permission to the procedure. Iron will creates an additional action, which is obviously negated. I guess it removes an instance of game procedure (paying costs), but that example isn't given. But I can't tell if 'negating' actually falls under the above definition of an effect.
Yes, both "ignore costs" and "negate effects" are themselves effects.
"Ignoring" a cost "adds... permissions to the game's procedures" and negation is a type of "Prevention Effect" (see here).