Rules, simple , you lob this spheriod lump of iron at a smaller ball which either you or somebody else has carelessly thrown away on piece of waste ground, then every body else hurls, rolls or tosses their lump at the same small ball or even worse tries to demolish your defenceless shot putting effort, by smashing into your ball, all done amongst wild cheering and suppressed gutteral threatening noises emitted from whosoevers boule was being attacked.
Ah, the Finnish rules. you must be holding a bottle in one hand to compete and take a draft every time a boule is hit, we made it to 2am, I think
