Determination Studio
Make UNDERTALE mods by clicking, not coding. See the real rooms, click a character, change what they say, press TRY IT.
Mac (Apple Silicon) and Windows 10/11 · free 3-day trial (dialogue + rooms)
* What you can do
All 336 rooms of UNDERTALE, drawn from your own copy of the game. Drag to move, scroll to zoom.
Toriel, Sans, shopkeepers, signs. Every one of the game's 16,000 lines is right there to rewrite.
Put a talk spot on a rock, a door or a tree. Walk up in the game, press Z, and it says your text.
Change the rooms of the game, and soon build brand-new ones.
Replace any song with your own MP3. It's converted for the game automatically.
Starting gold, HP, attack and defense. Random battles more often, less often or never.
Start a test straight into any monster or boss fight: Toriel, Papyrus, Undyne, Muffet, Mettaton EX and more.
Change any monster's name, HP, attack, defense, EXP and gold, and what it says in battle.
Rain, aimed shots, side waves, closing rings or spirals. Pick the bullets, speed and turn length.
Put a brand-new character in any room, using any sprite in the game, and give them lines.
Replace any sprite with your own PNG. Download the original, draw over it, swap it in.
When the player walks into a room: show text, give gold, heal, then start a fight.
* Trial and Pro
- 13-day free trial
Change dialogue, make anything talk and edit rooms. The clock only runs while Studio is open.
- 2Buy Pro
Unlocks every tool: music, stats, fights, and everything that comes next, forever.
- 3Your mods are never lost
Even after the trial you can open, test, save and share what you made.
* Coming next
The room creator, plus more attack patterns and story steps. Updates are free for Pro owners, and Pro accounts see no ads on this site.