Let me also chime in for this bug report, as this was actually on my list for quite a while, though not with Gravedigger.
The problem with Autoplay and casting spells is that Autoplay does not check for secondary requirements of a spell. This means that only the spell’s mana requirement is checked when deciding to cast the spell. I noticed this with “Gold Sense”, which requires the presence of Big V gems. If casting this spell is available (enough mana) but no Big V gems are on the board, Autoplay will continuously spam the spell. This leads to: a) no progression and b) [after manual intervention] the error message “Cannot cast that spell” being printed even in the menus after the end of the fight.
Suggested fix for Autoplay:
- check the mana requirement per spell
- check the secondary requirements before attempting to cast a spell
- check optional requirements to assess if casting a spell is valuable
The secondary requirements are:
- gems being present, e.g., for conversion spells or special spells like Gold Sense
- rows / columns / gems being valid as target
Optional requirements are:
- Ultimate Gems on board, e.g., for Spells like Divine Steed, Hellfire Gate, etc.
- Greed / Rage / etc. stacks present (e.g., for Wall of Anger or Greedy Rage)
- Status effect active, e.g., for Acid Cloud: enemy is poisoned / affected by Bad Juju
While 3) would be a real benefit to the autoplay mode for the player, 2) is required to remove endless loops. The current “workaround” for me is to create a dedicated “Autoplay” loadout and manually remove all spells with secondary requirements.