Undertale: First Playthrough Advice (Spoiler-Minimal)
How to approach your first Undertale run, what the ACT button does, and why your choices matter more than you think.
Read Everything
Undertale's writing is the game. Read every piece of flavor text, every NPC dialogue, every item description. The humor, heart, and foreshadowing are all in the text. Don't rush through it.
The ACT Button
In combat, FIGHT isn't your only option. ACT lets you interact with enemies — Checking them, talking, flirting, petting, threatening. Different ACT options weaken enemy attacks or open windows to Spare them. Experimenting with ACT options in each new fight is part of the experience.
Your First Run Should Be Blind
Like Outer Wilds, Undertale is designed to be discovered. Go in without a guide. Make choices based on how you feel in each moment. The game was designed assuming that first playthrough will be curious and imperfect — and it rewards both.
Save Frequently, But Not Everywhere
Save points fully heal you. Use them. However: the game tracks certain actions through saves and resets in ways that aren't immediately obvious. Play however feels right — just know that what you do matters to the game in ways you may not expect.
The Different Routes
Undertale has three broadly different routes depending on your choices. Without spoiling them: the most important thing is that your first playthrough should be authentic. Don't try to optimize it. Do what feels right. The game has things to say about whatever path you take.