  Randomness is an important factor in games, so much so that some games rely
almost purely on it for its outcomes and increase players' engagement with
them. However, randomness can affect the game experience depending on when it
occurs in a game, altering the chances of planning for a player. In this paper,
we refer to it as "input-output randomness". Input-output randomness is a
cornerstone of collectable card games like Hearthstone, in which cards are
drawn randomly (input randomness) and have random effects when played (output
randomness). While the topic might have been commonly discussed by game
designers and be present in many games, few empirical studies have been
performed to evaluate the effects of these different kinds of randomness on the
players' satisfaction. This research investigates the effects of input-output
randomness on collectable card games across four input-output randomness
conditions. We have developed our own collectable card game and experimented
with the different kinds of randomness with the game. Our results suggest that
input randomness can significantly impact game satisfaction negatively.
Overall, our results present helpful considerations on how and when to apply
randomness in game design when aiming for players' satisfaction.
