As players want to do awesome things and have an impact, it is your responsibility to make it clear what impact or consequences their actions have.
If this impact turns into hidden impact, a player might feel that their actions, features or resources are for naught and feel powerless or worse, useless or worst of all, make the game not fun.
Things that might have hidden impact
- Internal timers in fights they push back
- Their actions with NPCs or factions good or bad
- Bosses and Mini bosses expanding their resources to ‘overcome’ something of a player, eg Legendary Resistances