To make small, round shapes out of cardboard use an office hole punch (available also with funny hole shapes nowadays) or better still a DIY punching tool used to make holes in leather belts and the like »
A swamp and its family and relations are rarely seen and that is a pity as they offers interesting strategic challenges. Seem to favour static armies with a lot of guns where in fact it can also become a deadly trap if the enemy manages to outflank you? »