It involves completing a rune circle for an AW you don't actually want hoping for broken shards. When it fills up, you build and delete the AW, which empties the rune circle and then you fill it up again, hoping for more broken shards to use on the AW you want. It's a hassle, but if you're missing a lot of runes for that new AW you want, it can save a few weeks farming runes and shards in the tournaments.