Sans Fight Simulator

Quick start

Click the frame before any key counts. The corridor talk advances on Z. Hold the key only long enough for one line, then let go, or the next line waits. When the talk offers confetti, C is the key it names.

The next screen is Select Soul Mode. Up and down move the heart. Z confirms. Red is normal gameplay. Orange is the challenge where you must not stop moving. White is the challenge the menu calls one HP. Purple is the challenge that moves at half speed. After that, Keep Dialogue? asks whether to skip the talk. The lines are Skip All Dialogue, Skip All But Final, Keep Intro And Final, and Keep Dialouge, spelled that way on the last line.

The fight

Sans stands in the hall and the buttons along the bottom are Fight, Act, Item, and Mercy. Arrows move between them. Z confirms. Fight sends you into the box. Bones come up from the floor and down from the lid. Leave a gap and sit in it.

Some turns turn the heart blue. A blue heart falls and stands on the bones instead of flying freely, so the platform is the safe spot. Other turns fill the hall with blasters. That blue heart is Sans's gravity attack. It is separate from the orange, white, and purple challenges you picked at the start.

Item is the pie, the instant noodles, the snowman piece, and the legendary hero. The menu shortens the names. This build adds the soul challenges and the dialogue question, so a turn can differ from the fight you remember.

The other Undertale fight here is Omega Flowey . The Roaring Knight fight simulator is the first fight in the list.

Want another fan's Sans fight? Deltarune Fight keeps a separate Sans fight simulator.

For jcw87's Construct 2 clone with KARMA and Practice mode, open Bad Time Simulator .

How to dodge

In the real fight Sans attacks first. Most of the first half is a blue heart: gravity, so you jump. From the middle of the fight he mixes red and blue. Most hits also apply KARMA. Your HP keeps draining after the hit. You do not die from that drain until it finishes, unless a hit lands while you are at 1 HP. The Cloudy Glasses and the Torn Notebook slow the drain.

The opening string is his strongest attack. A blue slam puts you on the floor and bones rise where a red rectangle warned you. Then a red-heart bone wave with a gap. Then four sets of blasters: the sides, an X, the sides again, and two huge beams from the sides. For that last pair, hug the top or the bottom.

• Until your 13th attack, the heart stays blue. The turns are a bone gap of about eight small jumps, a long light-blue bone, random bone lines, four platform rooms, bones that slide sideways, and a platform with a blaster.
• You can stand on the green top of a platform. You can jump up through the white underside.
• If you accept his spare, bones fill the board and the fight ends. He does not attack during the offer, so you can heal as many times as you want first.

From your 13th attack until the 23rd, bones start showing up in the menu. Those deal 1 damage, have no KARMA, and cannot kill you. The patterns mix screen flickers, blasters aimed at you while the heart is red, slams into the walls, and vertical bone lines. When he slams you into a wall, jump away from that wall.

The last attack is four wall slams, a long fall to the right through bone waves, walls of rising bones, then blasters circling five times. After that, the slams cost 1 HP each and stop at 1. His special attack is a stall. Wait until his eyes close, then push the board left and then down until you can reach FIGHT. Only FIGHT moves the battle forward. Let KARMA finish before you eat.

This build adds the soul-mode question and the dialogue question before the hall. In the fight, arrows move the heart and Z confirms. A turn can differ from the one you remember.