A room full of viewers. One mercy decision.
Viewers Control Undertale on TikTok LIVE: Complete Tutorial for Beginners
Undertale lets chat do more than steer a character. A single confirm gift can commit an ACT choice, while a cancel gift can pull back from a menu. Build the stream around discussing the next decision together, then letting one viewer press the button.
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Before playing Undertale with viewers
Choose a single-player PC session and agree on a spoiler policy before opening the save. Back up your existing save files first and avoid saving over files you want to keep. Keep gift events disabled at save points and title menus; take charge yourself whenever a permanent choice is on screen.
Undertale: default PC keys
Default PC keyboard controls use arrows for movement, Z to confirm or act on the selected option, X to cancel, and C to open the menu. Enter, Shift and Ctrl also serve as alternatives. Check your own keybinds in the game's settings; the standard PC game does not offer full keyboard remapping, so also check any external remapper you use.
Control reference: Undertale Wiki: Settings and default confirm, cancel and menu keys.
Gift-to-key starter mapping
Try these starting settings for Undertale; choose gifts available to your audience.
| Gift example | Key and action | Hold duration (ms) | TikFinity screen |
|---|---|---|---|
| Rose | Left arrow: move left / select | 80 | 1 |
| Ice Cream | Right arrow: move right / select | 80 | 1 |
| TikTok | Up arrow: move up / select | 80 | 2 |
| Heart Me | Down arrow: move down / select | 80 | 2 |
| Finger Heart | Z: confirm / act on selected option | 60 | 3 |
| GG | X: cancel | 60 | 3 |
| Doughnut | C: open menu (optional) | 60 | 3 |
Why these durations suit Undertale
At 80 ms an arrow gives the SOUL a small nudge instead of a long trip across the bullet box. A 60 ms Z or X press is intended as one deliberate confirmation or cancellation, reducing the chance of holding through several text boxes. C needs only a tap to request the menu. These are starting values to try in an early encounter, not guaranteed dodges; game focus, input sampling and stream delay still matter.
Connect TikFinity to Undertale
- On the Windows PC running Undertale, open TikFinity Desktop and close the browser dashboard. Finish Setup and TikTok login. Capture the game in LIVE Studio or OBS, leaving both dialogue and the entire battle box visible.
- Open Actions & Events and create Confirm with Simulate keystrokes set to Z. Enable game compatibility mode and complete its installation prompt if needed. Use a 60 ms hold: 1,000 ms = 1 second. Duplicate this action for X, C and the 80 ms arrow taps, checking every selected key.
- Allocate Left/Right to screen 1 and Up/Down to screen 2, with directions on their own screens. Use screen 3 for Z, X and C so menu inputs run in order. Each screen is a queue; separate axes can overlap for diagonal SOUL movement. Add each screen URL as a Link source in LIVE Studio or Browser source in OBS.
- For every Sending a specific gift event, choose the named Undertale action from the table. Turn Repeat with gift combos off and begin with just one pending action per queue. Leave Skip on next action off and pause events before reading a major choice, rather than letting a backlog decide for you.
- In a quiet room away from save points, press the play icon for Left and focus the game within 5 seconds. Check one Z and one X press in a harmless interaction. The Event Simulator does not send keystrokes, so use action playback and confirm that each key releases before enabling gifts.
Undertale stream tips
- Turn-based fights and mercy choices make Z/X gifts dramatic but safe to stage while a menu is waiting. Agree on ACT or MERCY first, highlight it yourself, then invite one confirm gift. Z confirms the current selection; it is not a dedicated spare button, and a wrong choice can still matter.
- Bullet-dodging phases are real time. An 80 ms direction gift cannot react to delayed video reliably, so keep difficult SOUL patterns under streamer control or let chat attempt only familiar early encounters.
- Give a Genocide / True Pacifist spoilers warning before discussing routes, endings or late encounters. Ask chat to avoid unsolicited solutions and decide whether this stream permits route-changing decisions.
- Avoid saving over files you care about. Pause all events and clear queued Z inputs before touching a save point; resume after you have returned to an ordinary room.
- Leave C disabled for your first encounter if you want fewer interruptions. When you add it, show viewers that it opens a menu outside battle and does not create an extra combat turn.
Frame your Undertale stream
Place the arrow boxes underneath the battle box, with Z and X side by side as confirm and cancel. Keep the selected menu option, dialogue and health unobstructed. Use your camera above the game so viewers can read the choice before they send a gift.
The key boxes use CSS, with no game artwork. Alert display time controls alerts and TTS separately from key holds.
Undertale FAQ
Does a Z gift always spare the enemy?
No. Z confirms whatever is currently selected. Choose MERCY and the appropriate option first, and pause other gifts while explaining the decision.
Can viewers control every bullet-dodging phase?
They can try, but live video delay and queued inputs make reactive dodging unreliable. Begin with a familiar encounter and keep manual control available.
How do I protect an existing Undertale run?
Back up the save files before streaming, avoid saving over files you want to keep, and disable events at save points and important menus. A short hold does not protect a permanent choice.