Daniil Frolov wrote on Tue, Sep 21, 2010 02:03 PM UTC:
Yes, tower is actually analogue of crooked rook, that's why bishop's moves overlaps with it (and part of Knight-Errant's moves also overlaps with it, analogue of normal knight). Real rook analogue would be weak piece, making circular moves on adjecent cells (here 'king' can leap to any square, where rook would be able to go, but is not blockable).
Here is another natural piece for triangular board, it can be called unicorn (or rabbi? http://www.chessvariants.org/index/msdisplay.php?itemid=MSanglojewishche ), also circular-moving:
/\
/ \
----
/\ /\
/ \/ \
--------
/\ /\ /\
/ \/* \/ \
------------
/\* /\ /\* /\
/ \/ \/ \/ \
----------------
/\ /\ /\ /\ /\
/ \/* \/ \/* \/ \
--------------------
/\* /\ /\U /\ /\* /\
/ \/ \/ \/ \/ \/ \
------------------------
/\ /\ /\ /\ /\ /\ /\
/ \/* \/ \/* \/ \/* \/ \
----------------------------
/\ /\ /\* /\ /\* /\ /\ /\
/ \/ \/ \/ \/ \/ \/ \/ \
--------------------------------
It's restricted to board's quarter (look here to see it's bindings http://www.chessvariants.org/shape.dir/tc.html ).
I'm now making game with these pieces, maybe, it will be ready several days later.