Roulette vs Paper Lottery vs Amidakuji: Complete Comparison of Lottery Methods

"There are so many lottery tools available - which one should I use?"

Prize distributions at events, role assignments, team divisions - there are many situations requiring lotteries. However, fairness, transparency, and usability vary greatly depending on the lottery method.

This article provides a comprehensive comparison of major lottery methods to help you find the optimal approach for your scenario.

6 Major Lottery Methods

1. Paper Lottery

How it works:

• Write numbers or results on paper
• Place in envelopes or a box
• Participants draw

Fairness: ⭐⭐⭐⭐☆ Transparency: ⭐⭐☆☆☆ Usability: ⭐⭐⭐☆☆

Advantages:

• Simple preparation (only paper and pen needed)
• Everyone understands it
• No internet required
• Warm, analog feel

Disadvantages:

• Everyone must be in the same location
• Time-consuming preparation
• Cannot verify contents (lacks transparency)
• Risk of duplicates or omissions
• Not suitable for large groups

Recommended scenarios:

• Small gatherings (10 people or less)
• In-person events
• When you want to preserve an analog atmosphere

2. Garapon (Lottery Machine)

How it works:

• Numbered balls rotate inside
• Turn handle to draw balls
• Drawn number wins

Fairness: ⭐⭐⭐⭐☆ Transparency: ⭐⭐⭐⭐☆ Usability: ⭐⭐☆☆☆

Advantages:

• Visually clear
• Turning motion creates excitement
• Transparent - contents visible
• Creates event atmosphere

Disadvantages:

• Equipment rental/purchase required
• Heavy to transport
• Requires setup space
• Cannot use online
• Time-consuming setup and cleanup

Recommended scenarios:

• Large in-person events
• Year-end parties
• Festivals and bazaars
• When emphasizing presentation

3. Roulette (Web/App)

How it works:

• Names or numbers placed on circular board
• Press button to spin
• Winner determined by stop position

Fairness: ⭐⭐⭐☆☆ Transparency: ⭐⭐☆☆☆ Usability: ⭐⭐⭐⭐☆

Advantages:

• Visually entertaining
• Easy to operate
• Many free tools available
• Works on smartphones
• Flashy animations

Disadvantages:

• Only organizer operates (one-directional)
• Algorithm is opaque
• "Is this really random?" doubts remain
• Participants are passive
• Operations may be questioned

Recommended scenarios:

• Small casual events
• When emphasizing game-like elements
• When visual presentation is desired
• When trust is already established

4. Random Selection Tools (Excel/Google Sheets)

How it works:

• Use RAND or RANDBETWEEN functions
• Enter formulas in cells
• Recalculate to generate random numbers

Fairness: ⭐⭐⭐⭐☆ Transparency: ⭐⭐☆☆☆ Usability: ⭐⭐☆☆☆

Advantages:

• Can use existing software
• Can process large amounts of data
• High customizability
• No additional cost

Disadvantages:

• Requires formula knowledge
• Difficult to explain operation
• "Formulas can be changed" doubts
• Hard to see on screen share
• Participants are passive

Recommended scenarios:

• Internal company administrative lotteries
• When data is already in spreadsheet
• Small groups with established trust
• Lotteries with complex conditions

5. Rock-Paper-Scissors

How it works:

• Compete with rock, paper, or scissors
• Winner(s) advance or win

Fairness: ⭐⭐⭐☆☆ Transparency: ⭐⭐⭐⭐⭐ Usability: ⭐⭐⭐⭐☆

Advantages:

• No preparation needed
• Everyone knows it
• Immediate decision
• Completely transparent
• Creates excitement

Disadvantages:

• Frequent draws
• Time-consuming with large groups
• Difficult online
• Physical ability may influence results
• Multiple simultaneous winners possible

Recommended scenarios:

• Small groups (2-5 people)
• When immediate decision needed
• Casual situations
• Children's events

6. Amidakuji (Online)

How it works:

• Diagram combining vertical and horizontal lines
• All participants add horizontal lines
• Trace lines to determine outcome

Fairness: ⭐⭐⭐⭐⭐ Transparency: ⭐⭐⭐⭐⭐ Usability: ⭐⭐⭐⭐☆

Advantages:

• Mathematically guaranteed fairness
• All participants involved in process
• No one can manipulate results
• Works both online and offline
• Large group support (up to 299 people)
• Easy sharing via URL

Disadvantages:

• Online version requires internet connection
• Explanation needed for first-time users
• Takes time until all participants join

Recommended scenarios:

• When fairness and transparency are critical
• Online events
• Company parties
• Large group lotteries
• When remote participants are involved

Detailed Comparison Table

Item	Paper Lottery	Garapon	Roulette	Excel	Rock-Paper-Scissors	Amidakuji
Fairness	○	○	△	○	△	◎
Transparency	△	○	△	△	◎	◎
Usability	○	△	○	△	○	○
Setup Time	5-15 min	30-60 min	1-5 min	5-10 min	0 min	1-5 min
Capacity	10 or less	100 or less	No limit	No limit	5 or less	Up to 299
Online Support	×	×	○	○	△	◎
Cost	Free	Paid	Free	Free	Free	Free
Participatory	△	△	×	×	◎	◎
Recording	△	△	○	◎	×	◎

Scientific Analysis of Fairness

Mathematical Definition of Fairness

Fair lottery means:

1. Equal probability: All outcomes appear with equal probability
2. Independence: Previous results don't affect next results
3. Unpredictability: Results cannot be predicted in advance
4. One-to-one correspondence: All participants get different results

Mathematical Evaluation of Each Method

Amidakuji:

• Equal probability: ◎ (All paths equally probable based on horizontal line positions)
• Independence: ◎ (New amidakuji created each time)
• Unpredictability: ◎ (Difficult to predict with 3+ horizontal lines)
• One-to-one correspondence: ◎ (Mathematically guaranteed)

Learn more: How to Scientifically Prove Lottery Fairness for detailed explanation

Roulette:

• Equal probability: △ (Algorithm dependent)
• Independence: ○ (Independent if true random)
• Unpredictability: △ (Limitations of pseudo-random)
• One-to-one correspondence: ○ (Depends on design)

Rock-Paper-Scissors:

• Equal probability: △ (Affected by psychological factors)
• Independence: △ (Can read opponent's patterns)
• Unpredictability: △ (Has strategic elements)
• One-to-one correspondence: × (Draws and multiple winners occur)

Recommended Lottery Methods by Scenario

Corporate Events (Prize Distribution)

Participants: 50-200 people Priorities: Fairness, transparency, excitement

Recommended: Online Amidakuji

• High satisfaction with full participation
• Remote employees can participate
• Exciting 3D presentation
• Records maintained

Alternative: Garapon (if budget available and in-person event)

Small Drinking Parties (Choosing Organizer)

Participants: 5-15 people Priorities: Convenience, satisfaction

Recommended: Rock-paper-scissors or Online Amidakuji

• Rock-paper-scissors: For immediate decision
• Amidakuji: When fairness is priority

Alternative: Paper lottery (if preparation time available)

School Role Assignment

Participants: 20-40 people Priorities: Fairness, educational value

Recommended: Online Amidakuji

• Process is visualized
• Learn democratic decision-making
• Improve digital literacy

Alternative: Combination of discussion + lottery

Online Seminars (Participant Benefits)

Participants: 100-300 people Priorities: Transparency, large group support

Recommended: Online Amidakuji

• Supports up to 299 people
• Easy sharing via URL
• Can be done via Zoom screen share

Alternative: Random selection tool (if reliability can be explained)

Large Events (Visitor Prizes)

Participants: 500+ people Priorities: Efficiency, presentation

Recommended: Garapon or Digital lottery system

• Garapon: As stage event
• Digital: When efficiency is priority

Note: Also check legal considerations for prize lotteries

Frequently Asked Questions

Q1: Which is the fairest lottery method?

Mathematically, amidakuji is the fairest. Here's why:

• One-to-one correspondence is mathematically guaranteed
• All participants involved in process
• High unpredictability
• Extremely high transparency

Q2: Are online lottery tools trustworthy?

It depends on the tool. Criteria for trustworthy tools:

• Process is visualized
• Mechanism involving all participants
• Design preventing organizer-only operation
• Open source or publicly explained mechanism

Q3: Which creates more excitement - roulette or amidakuji?

Roulette: Temporary excitement from visual flash Amidakuji: Sustained unity through full participation

Choose based on purpose:

• Presentation focus → Roulette
• Satisfaction focus → Amidakuji

Q4: Which is simpler - paper lottery or online amidakuji?

Preparation simplicity: Online amidakuji (just create URL) Explanation simplicity: Paper lottery (everyone knows it) Large group support: Online amidakuji (up to 299 people)

For first-time use, explaining participation method in advance ensures smooth operation.

Q5: Can amidakuji really not be manipulated?

How Online Amidakuji works:

1. All participants add horizontal lines
2. Results unknown until everyone joins
3. Administrators cannot know results in advance
4. Cannot modify after lottery execution

Therefore, no one can manipulate the results.

Summary

How to choose lottery methods:

Prioritize fairness and transparency: → Online Amidakuji

Immediate decision (small group): → Rock-paper-scissors

In-person excitement (with budget): → Garapon

Easy casual use: → Roulette

Data processing needed: → Excel/Spreadsheet

Analog atmosphere: → Paper lottery

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Choose the lottery method that fits your purpose to create fair and satisfying events!