Talk:Cassiopeia/@comment-25798210-20160630203704/@comment-24055932-20160702045254

It's a fair trade-off. You lose out on a unique effect (which would have been most likely magic pen, tenacity or slow-resist) and in trade get to skip boots ( or ) and have an effective free slot.

It's a rather big deal as Cassiopeia is one of the kind of champions that needs everything. First you need Mana to actually be able to deal damage. You want AP & CDR to increase your damage, you need defensives to migitate damage, you need utility to be able to kite and chase (e.g. Rylai's). At some point you need magic pen.

Even as full items, fitting your whole build into 5 slots is rather difficult. Even more so if you're not 40 minutes in, because then you won't have full items but rather item parts. So to get as many of the stats you want as quickly as possible, having as many slots as possible is extremely beneficial