Icehouse pieces, or Icehouse Pyramids, Treehouse pieces, Treehouse Pyramids and officially Looney Pyramids, are nestable and stackable pyramid-shaped gaming pieces and a game system.
 The game system was invented by Andrew Looney and John Cooper in 1987, originally for use in the game of Icehouse.
Treehouse is a game in which players try to get their configuration of Icehouse pieces to match the central configuration, shared by all players.
 The rolling of the special "Treehouse Die" tells the player what kind of move to make to change his own or the central configuration, and then he does so to best move towards the goal.
Mutant Meeples is a 2012 board game designed by Ted Alspach and published by Beziér Games and Pegasus Spiele.
 The game has been inspired by "Ricochet Robots" by Alex Randolph.
IceTowers is a turnless strategy game designed by Andrew Looney and published by Looney Labs.
 The game is played with a set of "Icehouse" pieces, with each player assigned a specific color.

Question: Mutant Meeples and Icehouse pieces are both what?
Answer: game