Ask experienced players what changed most between Slay the Spire 1 and 2 and energy comes up fast. You still get 3 energy per turn, but the guaranteed energy relic from the Act 1 boss is gone, so turns have to be planned instead of improvised. These tips are about spending those 3 points on purpose.
Why energy feels tighter now
In the first game you could plan around an energy relic arriving from the Act 1 boss. In STS2 there is no such guarantee — the act reward is a choice of Ancient Blessings instead, and energy blessings do not always show up.
The trade is that cards are stronger on average. So the question each turn is no longer "how do I spend all my energy" but "which two or three cards actually move this fight". Our STS1 vs STS2 guide covers the other old habits worth updating.
Read the intent, then spend
Before playing anything, check what the enemy is doing. Big attack incoming: your plan is block plus tempo. Enemy buffing or charging: that is your free turn — put everything into damage or setup, because block played on a turn the enemy skips is usually wasted.
The most common waste is blocking 15 against a 6-damage hit while your kill needs one more turn. The second is spending a whole turn on setup when the enemy telegraphed something huge. Both are intent-reading problems, not energy problems.
Cards that stretch a turn
Zero-cost cards are the cheapest way to act more than three times a turn. Not all of them are good, but one or two efficient ones add real output for free. Filter the card database by cost and see which fit your character.
Card draw is energy efficiency in disguise: a Pommel Strike-style card turns one energy into damage plus the card you actually needed. If your turns feel starved, the fix is usually draw, not more cards.
Energy generation still exists — Bloodletting-style cards, energy potions, a few relics — but treat it as premium support, not a plan. In STS2 every extra energy is paid for in health, cards, or tempo, so spend it on the turn that matters.
Exhaust decks manage energy from the other side: burning filler mid-fight means every future draw is a card worth playing. New to the mechanic? The exhaust wiki page explains it in one minute.
Relics and potions that buy tempo
When choosing rewards, energy-adjacent relics punch above their weight: extra energy on turn one, cost reductions, or extra card plays all turn a 3-energy deck into something bigger. Skim the relic list before an elite so you know which rewards actually help your plan.
Potions are instant energy too — a block potion is block you did not spend energy on, a strength potion is damage you did not draw into. Carry one into every elite and boss, and check the potion list for what shops tend to stock.
A one-run drill
Take one run and, every single turn, ask two questions: what kills them fastest, and what do I need to survive until then? Then play only the cards that answer those two questions.
Most players discover they were spending energy on cards that answered neither — setup for turn six when turn four was the real problem. Fix the order and the same deck starts winning fights it used to lose.