The text of "Reap what´s sown" says: "Action: Each player with X or more total developments may discard his hand and draw X cards" But it does not tell what X is. Is the number of X decided by the player who plays this card?

The "Blue Horrors" text tells me: ""Action: When this unit leaves play, you may put another unit named Blue Horrors into play from your hand (can be played in any zone". Do I have to pay the costs for the second "Blue Horrors", or is it free?

X is the cost of the card.

you can put it for free. (you don't use the normal way to put a unit into play)

X is whatever you want to pay, but only players with that many or more developments can participate in the cards effect. It would be really cool if it was not an optional effect, playing it for 0 to force everyone to discard their hands would have made it good. The way it is though, its just okay.

Ah, understood. Thank you very much!

Katsuyori said:

You do not have to pay the cost of the replacement Blue Horrors (aka the second one is free).

Thanks, Toberk. That helped me a lot!