Last time, I described changing each element to specialize in one resource and promised to describe metal, changing range, and how that eventually simplified the rest of the game.
Changing range is a bit unintuitive for something that seems as stable and inert as metal. Thematically, it relies on the idea of metal being conductive. The key card to make metal—and range as a focus in general—was pin. Pin adds a status effect to one's partner that makes any range change cause damage. Creating it suggested other cards that changed range with an additional effect, eventually settling on reducing the partner's energy.
Originally, pin could be played at any range and had a one energy cost. This inadvertantly made metal very strong: A pin could be followed by two standard movement actions from full energy guaranteeing two points of damage. Partners had very little ability to react and mitigate damage since players always had access to movement.
Changing the playable range to only close introduced some counterplay, but it wasn't sufficient. Fire and earth cards would always play first against metal cards and so they could avoid the initial pin. But the move action always happened before any other element, so once a pin was successful, the caster could always guarantee the damage. Changing movement to happen after elemental actions made pin essentially worthless since spamming fire or earth cards would guarantee it would be interrupted and not be cast.
My current solution consists of treating all neutral cards, currently moving and resting, as the same element as the parter's element. This change makes card speed determine which card is resolved first and gave me a way to tune pin vs. potentially problematic cards. The other change was to remove the card interruption from opposing elements: Now fire and earth cards could be played and metal would still come out if the range was still close.
With sequence energy and card interruption removed, I had thought I had removed everything I was going to. But there was one more mechanic that I ended up dropping that I'll discuss next time: drawing a card every turn.