Play on an open empty map set to 18 starting girders (which happens to be the default number so no need to change);
No Full Girder blocks. It is not allowed to fully block a enemy worm with your girders (even though blocking your own worm is allowed if you want to give it shelter)
We are using anti fort rule. If you place girders 2 times in a row then you will have to wait 2 turns before placing any girders again.
No horizontial girders straight on a worm's head. To prevent lame play (since you have infinite girders) it is counted as a cow to place a horizontial girder straight on a worms head (must be at least 1 small girder away)
In other tourneys less skilled players have won by getting lucky crates. so the crates are removed.... but if both players agree then you can use the crate scheme.