If you learned to play Icehouse from that blue booklet that
was included in the first 100 game sets and haven't played much
since, you need to be aware of these official changes to the rules.
No More Walls (March 1992): All rules relating to
theoretical boundaries called Walls were dropped from the standard
ruleset.
A Softer Penalty for False Icehouse Calls (July 1998):
The penalty for making an incorrect Icehouse call was changed,
from giving away one of your attacking pieces to giving away
a piece from your stash pad.
The Timer Becomes Mandatory (June 2001): The once-optional Timer rule became
standard at tournaments as
long ago as 1991, and it remains the best known solution to the
famous stagnation problem.
We finally realized it should be an official rule.