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framework
Behaviour & motivation

Hooked Model

Trigger → Action → Variable reward → Investment: the loop behind habit-forming products.

⏱ 11 minBeginnerBy Nir EyalSince 2014
1234Habit
Use it when

Designing for repeat use and habits, responsibly.

You'll walk away with

A hook canvas for one habit, plus an ethics check.

Step 1 · The idea

Products that people use without being asked

Nir Eyal's book Hooked: How to Build Habit-Forming Products (2014) describes a four-step loop — Trigger → Action → Variable reward → Investment — that habit-forming products repeat until users come back on their own.

The goal is to move people from external triggers (a notification) to internal triggers (a feeling), so the product becomes the automatic answer to a need.

Hooked is closely related to Fogg (the Action step is B = MAP) and Octalysis (variable rewards are drive 7). Together they explain most engagement design.
Step 2 · Play with it

The four steps of a hook

Select a step to see what it means and a real example.

TriggerActionVariable rewardInvestmentRepeat → habit
Step 1 of 4

Trigger

What makes the user start?

The cue to act. External triggers are notifications, emails, buttons. Internal triggers are feelings — boredom, loneliness, uncertainty — that the user learns to connect with your product.

Example: External: “Riya tagged you in a photo.” Internal: feeling bored in a queue → open Instagram.

Step 3 · Real product

One loop in Instagram

Follow a single cycle from notification to posting.

1:14 PM
Instagram
now
riya.designs and 12 others liked your photo.
Step 1

External trigger

A notification pulls you in. Early on, most visits start like this.
Trigger · external
Instagram♡ ✉
↓ scroll
Step 2

Action: open and scroll

The action is tiny: tap and scroll. No thinking needed, which is exactly why it becomes automatic.
Action
♥ 48 likes
up from 31 last time
💬 “Love this colour palette!”
New posts from 6 friends
Step 3

Variable reward

How many likes? Who commented? What's new in the feed? The uncertainty is what makes checking rewarding.
Reward · tribeReward · hunt
New post
Write a caption…
Share
Step 4

Investment

You post a photo of your own. It took effort, and it will bring likes and comments — which become the next trigger.
InvestmentLoads next trigger
Waiting for a meeting…
5 minutes, nothing to do
📱
Thumb opens Instagram before you decide to
Step 5

Internal trigger forms

After many loops, boredom itself becomes the trigger. That's when a habit has formed.
Trigger · internal

Illustrative walkthrough. Screens are simplified recreations, not real screenshots.

Step 4 · Try it

Hook canvas for your product

Fill in each step for one habit you want to build. The loop updates as you type.

1
Trigger

8 PM “Hungry? Your usual is 1 tap away” notification
Later, internally: Hungry and tired after a long day at work

2
Action

Open the app and tap Reorder

3
Variable reward

Today's offer, a new dish or a faster delivery time

4
Investment

Save favourites and address, rate the meal

↺ The investment should make the next trigger more likely.

Use it responsibly

The Manipulation Matrix

Eyal asks two questions before you build a habit: would you use it yourself, and does it materially improve users' lives?

Facilitator

Would use it themselves · improves users' lives

Peddler

Wouldn't use it · claims to improve lives

Entertainer

Would use it · doesn't really improve lives

Dealer

Wouldn't use it · doesn't improve lives

Aim for Facilitator. In money, lending and kids' products, the bar should be even higher.

Watch out

Common mistakes

✓ Do

  • Start from a real, frequent user need
  • Make the action as easy as possible
  • Let the investment improve the product for the user
  • Aim to move from external to internal triggers
  • Check yourself with the Manipulation Matrix

✗ Avoid

  • Hooks for things people only do once a year
  • Rewards that are random but worthless
  • Notification spam as a substitute for value
  • Investments that only benefit the company
  • Building compulsion into products for vulnerable users
Cheat sheet

Hooked Model in one screen

THE LOOP
1 TRIGGER      external (notification, email, button) → internal (emotion)
2 ACTION       simplest behaviour in anticipation of reward  (B = MAP)
3 VARIABLE     tribe (social) · hunt (resources/info) · self (mastery)
  REWARD
4 INVESTMENT   content, data, followers, reputation, skill → loads next trigger

HABIT ZONE     frequent behaviour + perceived usefulness

MANIPULATION MATRIX
                 improves lives   doesn't
  I'd use it     Facilitator      Entertainer
  I wouldn't     Peddler          Dealer
Use it at work

Figma template

A ready-made canvas for running this framework with your team. Free, editable, and it works in Figma and FigJam.

Preview of the Hook canvas template
Figma & FigJam · free

Hook canvas

  • Trigger → Action → Reward → Investment loop
  • Variable reward types
  • Manipulation Matrix
  1. 1Download the SVG, or copy it to your clipboard.
  2. 2In Figma or FigJam, drag the file onto the canvas — or paste with ⌘V / Ctrl V.
  3. 3Everything arrives as editable layers: type in the boxes, add stickies, duplicate rows.
Check yourself

Quick quiz

Get all three right to complete the lesson.

Question 1

1. Feeling bored while waiting and opening an app without thinking is an example of…

Question 2

2. Why does the Investment phase matter?

Question 3

3. Before building a hook, Nir Eyal suggests you ask…

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Sources and further reading

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