Members-Only Lottery: Lock Your Draw to Your Company or School Domain

When you run a lottery for your company or school, the standard worry is: "What if the URL leaks and outsiders join?" Links get forwarded in chat, screenshotted, and posted to wherever. Once a URL is in the wild, anyone can join.

Amida-san's Organizer Plan (Pro) lets you add two layers of access control -- require sign-in, and restrict to specific email domains -- so even if the URL leaks, outsiders simply can't join. This article shows how to lock a lottery down to a single organization.

The leak risk of "anyone with the URL can join"

Most online lotteries are URL-only: if you have the link, you can participate. That's friction-free, but it's a problem when you need to keep things internal.

URLs travel farther than you think

• Chat messages get forwarded into unrelated channels
• Screenshots end up on social media
• Former employees and alumni still have access to old URLs
• Clients and vendors sometimes get the link by mistake

Outsider participation breaks the draw

If a stranger sneaks into a prize draw, an employee who should have won might lose. If a role assignment includes someone who doesn't actually belong to the team, that role ends up assigned to nobody useful. Without a guarantee that "every participant is actually a member," the tool just isn't fit for serious work use.

Amida-san's two-step participation control

The Organizer Plan (Pro) gives you two access controls you can enable when creating an event.

1. Require sign-in

Force participants to sign in before they can join. This blocks fully anonymous participation and ties every participant to a real account.

2. Email domain restriction

Specify the email domains you want to allow (for example, @example.com). Only accounts with those domains can join. Even if the URL leaks externally, anyone from another domain hits the door and bounces.

Allowed domain: example.com
=> [email protected] can join
=> [email protected] cannot join

Schools can lock the event to their school-issued domain; companies can lock it to their corporate domain. Either way, anyone who only "knows the URL" is shut out at the technical level.

How to set it up

1. Subscribe to the Organizer Plan (Pro) and sign in
2. Open the participation restriction settings on the event creation screen
3. Turn on "Require sign-in"
4. Enter the email domains you want to allow
5. Create the event and share the URL the same way you always do
6. Participants can only join if they sign in and meet the allowed conditions

The way you share the URL doesn't change. What changes is the peace of mind: a URL alone is no longer enough to participate.

Compared to common alternatives

Method	Blocks outsiders	Setup effort	Confidence for internal use
Share URL only (typical lottery)	No	None	Low
Distribute a password separately	Same risk once leaked	Medium	Medium
Amida-san: require sign-in	Blocks anonymous joins	Low	High
Amida-san: domain restriction	Blocks other domains	Low	Very high

Great fits

Internal corporate events

Whether it's a year-end party prize drawing or assigning routine duties inside a department, you can keep the activity strictly inside the company. No IT-approval-required tool to install -- just share a URL.

Schools and educational institutions

Lock committee selections and seat assignments to students, faculty, and staff. Parents and unrelated outsiders can't accidentally end up in the draw.

Healthcare and shift management

When you do shift or assignment lotteries, guarantee that only your actual staff can participate. The result is usable as-is for operational scheduling.

Frequently asked questions

Q1: Can I use participation restrictions on the free plan?

No. Both sign-in requirements and email domain restrictions are Organizer Plan (Pro) features. On the free plan, anyone with the URL can join.

Q2: Can I allow multiple domains?

Yes. You can list several domains -- useful for group companies, multiple campuses, or partner organizations.

Q3: Are email addresses shown to other participants?

No. Emails are only used to verify eligibility. The result screen shows display names (nicknames, etc.) -- never email addresses.

Q4: Is the sign-in process complicated?

Not at all. Participants just sign in -- no special setup, and it works the same on smartphones and PCs from the same URL.

Q5: How much does it cost?

The Organizer Plan (Pro) is $39 / month or $390 / year (annual saves about 2 months). Participation restrictions, re-draws, unlimited result downloads, and more are bundled in.

Lock down your lotteries with the Organizer Plan (Pro)

Members-only lotteries are part of Amida-san's Organizer Plan (Pro). For $39 / month (or $390 / year -- about 2 months saved), you get participation restrictions, re-draw, unlimited result downloads, ad-free events, and the rest of the organizer toolkit. If "what happens if the URL leaks" is a question you can't ignore, give it a try.

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Want to see everything the Organizer Plan (Pro) offers in one place? Take a look at every Organizer Plan (Pro) feature, explained.

Other Pro Plan features

The Organizer Plan (Pro) bundles a full set of tools for running lotteries inside an organization. The following articles cover each feature in detail.

• Decorate your event page (event decoration)
• How to redraw a lottery (redraw + history)
• Save lottery results to CSV / Excel (unlimited downloads)
• Amida3D animation effect (unlimited Amida3D)
• Cancel a mistakenly created event (suspend / restore)
• Remove or edit lottery participants
• Prevent accidental edits by participants (account lock)
• Ad-free lottery (no ads for participants)
• 365-day long-term storage (extended availability)
• Issue a receipt (for corporate / expense reports)

All of these are included in the Organizer Plan (Pro) at $39 / month or $390 / year.