Undertale: First Playthrough Advice (Spoiler-Minimal)

Read Every Word

Undertale's writing is the entire game. Not in a literary-pretension way — in a practical, mechanical way. The humor is in the text. The character development is in the text. The foreshadowing and secrets and emotional payoffs are all embedded in dialogue, flavor text, and item descriptions that are trivially easy to skip. Don't skip them. Talk to every NPC twice. Read every sign. Check every trash can. The game is short enough that thoroughness never costs much time, and its rewards are distributed across exactly these small moments of attention.

The ACT Button Is the Core System

In every combat encounter, you have four options: FIGHT, ACT, ITEM, MERCY. FIGHT deals damage. MERCY spares an enemy (if they're in a spareable state). But ACT is the game's actual combat system — and most first-time players underuse it.

ACT options are unique to each enemy and change what's possible: checking an enemy reveals their HP and a personality hint, talking to them might open a window to flee without fighting, specific actions (petting, flirting, flexing, joking) affect their emotional state and often lower their attack intensity or make them spareable. The key insight: enemies that seem impossible to spare usually require a specific ACT sequence first. Experimenting is always correct.

Bullet Patterns Are Learnable

The battle system is a top-down bullet-hell minigame where you navigate a small heart through enemy attacks. Each enemy has a distinct pattern set. Patterns you fail once become readable the second time — the game respects the knowledge you build across attempts. If a bullet pattern feels impossible, you're probably trying to dodge everything simultaneously instead of finding the safe lane. Most patterns have a central empty space or a rhythm you can move with.

The game is not trying to kill you. It's trying to show you something. Every difficult encounter gets easier once you understand what the enemy is feeling — which is almost always legible in their attack patterns if you pay attention.

Your First Run Should Be Blind and Genuine

Undertale was designed with the assumption that your first playthrough will be imperfect, curious, and made with real emotions rather than optimized choices. Go in without a guide. Make choices based on how you actually feel in the moment. Don't try to achieve a specific outcome — play naturally and let the game respond to you. Whatever route you take, the game has something specific to say about it. None of the paths are wrong.

Save Points Heal You — and Track More Than You Know

SAVE points fully restore your HP and are scattered throughout each area. Use them consistently. However: Undertale's SAVE system tracks more than your position. The game remembers actions across save files and resets in ways that aren't explained and aren't obvious. Play however feels right on this first run — just know that the game is paying attention to more than you might expect, and that this is intentional rather than a technical quirk.

The Areas

The Underground is divided into distinct zones, each with its own visual style, enemy types, and resident characters. You'll pass through the Ruins (the tutorial zone, gentle and melancholy), Snowdin (a winter village with the game's funniest characters), Waterfall (atmospheric and emotionally dense), Hotland (the most mechanically complex area), and the Core. Each area has a boss at the end who embodies the emotional themes of that zone. The bosses are the game's best writing.

After Your First Run

Whatever you did on your first run, there is more to see. Undertale has meaningful replay depth — different routes reveal different perspectives, different character histories, and different things the game has to say about the choices you made. If you finish the game and want to understand it more fully, a second run with different choices is worth taking. What you discover will recontextualize everything you saw the first time.