8 steps

Animation that feels alive

For: Menus, characters and effects that move but feel stiff.

Almost all motion in games is a few curves applied with taste. Learn the curves first, then the spring, then the tricks that use them. The order matters because each step is built from the one before.

The steps, in order

1. 1

   Code recipe

   Lerp and smoothstep

   The small helpers for blending one number into another: halfway between two values, turning health into a bar, a soft fade near an edge. They are the building blocks behind nearly every smooth effect in a game.

   Why here: The smallest piece: moving from a to b over time, and why doing it "a bit closer every frame" breaks on a slow machine.

2. 2

   Code recipe

   Easing functions

   The complete set of movement curves that make things start softly, land softly, swing past the end or bounce. Your game stops looking stiff, because nothing moves at one flat speed any more.

   Why here: Then the curves: ease in, ease out, overshoot. This is most of what people mean by "juicy", and it is a lookup, not art.

3. 3

   Wiki entry

   Animate a value through several keyframes, each stretch with its own feel

   A logo that swings in, waits, and drops out needs more than one start and end value. Here is how to sample any moment of such a track, what to return before the first and after the last point, and how to hold a value for a while or make a sudden jump.

   Why here: Curves applied to several keyframes make a track; this is how a menu slide or a door opening is actually built.

4. 4

   Code recipe

   Spring motion

   Makes a value chase its target as if it hung on a spring, fast at first, then slowing, with an optional wobble. You can change the target at any moment and it reacts naturally, and a slow frame never breaks it.

   Why here: A spring replaces a curve where the target keeps moving: cameras, cursors, followers. One formula, two knobs.

5. 5

   Code recipe

   Squash and stretch

   The oldest trick in animation: things stretch when they move fast and squash when they land, while keeping their size. It makes even a plain box feel alive.

   Why here: The first trick built on curves: shape follows speed. It is why a ball reads as rubber and a crate as wood.

6. 6

   Code recipe

   Idle sway

   Makes a character that stands still look alive: it breathes and sways a little, with no visible loop. Two characters never move in step, so a crowd looks like people and not like a copy.

   Why here: Things that stand still should not be still. Layered noise gives breathing and sway without a single hand-made keyframe.

7. 7

   Wiki entry

   Trigger sounds and effects at exact moments, even when a frame is slow

   Footsteps, sword swooshes and fireworks tied to moments in an animation either get skipped when the game hiccups or play twice. Here is how to make every marker go off exactly once, in order, including in animations that repeat.

   Why here: Sounds and sparks on a timeline must fire once, also when a frame is slow. This bug hides until the game ships.

8. 8

   Code recipe

   Particle burst

   A quick spray of sparks, dust, coins or smoke. Every particle gets its own speed, life and spin, slows down in the air and falls with gravity, and a burst is always well filled.

   Why here: Last the burst: with easing, springs and timing in hand, a particle effect is composition, not a new skill.

At the end

Nothing in your game moves at a constant speed anymore, and your AI has the math for every motion you describe.

What this rests on

Talks, articles and research from outside this wiki, so you are not taking our word for it.

• Juice It or Lose It (Martin Jonasson and Petri Purho, GDC Europe 2012 (Independent Games Summit), GDC Vault, 2012)

  Shows live how a dull block-breaking game becomes satisfying just by adding small effects like particles, bounces and sound, which is the core idea of juice.

• Vlambeer co-founder shares advice on building better action games (Alex Wawro, Game Developer (reporting on Jan Willem Nijman's talk "The Art of Screenshake", Control Conference Amsterdam), 2014)

  Describes how Nijman turned a plain shooter into a great-feeling one with about 30 small tweaks such as screen shake and recoil, one at a time.

• The 12 principles of animation in video games (Jonathan Cooper (excerpt from the book Game Anim), Game Developer, 2019)

  Explains the classic twelve animation principles from Disney animators and how games like Cuphead and Shadow of the Colossus use them, including where responsiveness limits them.

• 12 principles for game animation (Christopher Totten, Game Developer, 2021)

  Walks through each animation principle, such as squash and stretch, anticipation and timing, and shows how to adapt it when a game needs accurate collisions and instant control.

• Instant Game Feel - Springs Explained (Chad Cable, Game Developer, 2022)

  Explains springs as a simple way to make buttons, cameras and meters move with natural bounce, controlled by just two settings: how bouncy and how snappy.

Say this to your AI

Follow the Spielerando learning path "Animation that feels alive" (get_path animation-that-feels-alive) for my game, step by step, and tell me at each step why it comes now.

Or skip this and connect the MCP: your AI then finds all of this by itself.Connect the MCP