Lairs · Board game rules
How do conserved cubes interact with energy strikes?
Quick answer
Conserved cubes count as Fresh cubes for penalty purposes, so a "strike" that fatigues Fresh cubes can fatigue a Conserved cube too.
Details
When a Monster or Trap strikes you, the penalty (often to fatigue a certain type or number of cubes) must be fulfilled according to its specific wording [p.7 — PENALTIES & FATIGUE]. If the penalty calls out Fresh cubes specifically, Conserved cubes are treated as Fresh cubes and are therefore eligible (and may be required) to satisfy that penalty [p.7 — PENALTIES & FATIGUE].
Outside of being used to fulfill a penalty, Conserved cubes are otherwise untouched by the normal turn flow — during your Refresh step, Spent cubes move to Fresh and Fatigued cubes move to Spent, but Conserved cubes do not move [p.7 — ON EVERY TURN]. This is what gives them their special value: a Conserved cube can effectively be spent twice, once moved into your Fresh basket (and then spent normally), unless it gets caught by a penalty that targets Fresh cubes first.
Watch out: If you're hit by a strike that fatigues "Fresh" cubes and you have a Conserved cube available, the Builder/game may require you to fatigue that Conserved cube (since it counts as Fresh for penalties), losing its "spend twice" bonus — plan your Conserve action with this risk in mind [p.7 — PENALTIES & FATIGUE].