How this skill behaves (read first)
This is a generative skill. The default failure modes: interrupting for everything (modals for success messages, tips, newsletters — attention spent like it's free), trapping users (no visible close, no Esc, stacked modals), and vague choices ("Are you sure?" → Yes/No). A modal takes the whole interface hostage — that's justified only in high-stakes moments, and the price is paid back with crystal-clear purpose and effortless exit. This skill gates:
- Gate the interruption itself — is a modal even justified here? The most important decision happens before any design.
- Apply the always-true core — purpose in the title, explicit buttons, easy dismissal, focus management.
- Surface the type and timing decisions (popup/fullscreen/popover/bottom sheet, permission priming) with trade-offs.
Then it hands off to ux-heuristics-audit, ux-accessibility-audit, ux-aesthetics-audit, ux-microcopy-audit, and ux-dark-patterns-audit for validation.
Step 0 — Gate the interruption (the decision that matters most)
A modal blocks everything. It earns that only for high-stakes moments:
- Confirming destructive or irreversible actions (delete account, discard draft) — show impact ("12 files will be deleted").
- Critical errors or warnings (system restart, unsaved changes at risk).
- Information required to continue the current task (login to save, payment details).
Everything else — success messages, tips, FYIs, promotions — uses non-modal patterns: inline messages, toasts, banners, popovers. Also establish:
- Who triggers it? User-initiated modals (clicked a button) are expected; system-initiated modals (timed popups, upgrade nags) interrupt without warning — avoid unless truly urgent (session expiry, critical update).
- Timing — never interrupt high-stakes flows in progress (mid-checkout is the classic crime).
- Platform — desktop alert vs. iOS alert / Android dialog conventions; bottom/action sheets for mobile action lists.
If the content fails the high-stakes test, stop designing a modal and recommend the inline/toast alternative.
The always-apply core (correct for every modal that survives the gate)
Purpose, title, buttons
- The title carries the whole message — users skim or skip body text. "Discard draft?" not "Warning." Body text adds the why and context; nothing vital lives only in the body.
- Explicit button labels answering the title: ❌ "Yes" / "No" / "Cancel" ✅ "Discard draft" / "Keep editing." Users must know what each button does without reading anything else.
- Maximum two action buttons. A third ("Learn more") leaks users out of the decision.
- Never blame or shame in opt-out labels ("No thanks, I hate saving money" → dark-patterns flag).
Dismissal is a right, not a feature
- Multiple visible exits: Close/Cancel button + the × in the corner + Esc on desktop / Back on mobile.
- Click/tap outside closes it — when no entered data would be lost; suppress only when dismissal would destroy work.
- Never stack modals. A modal on a modal is a hostage situation with extra steps.
Focus and attention mechanics
- Dark overlay behind the modal — focuses attention, blocks outside interaction, doubles as a close target.
- Keyboard focus moves into the modal on open (onto the primary action); all controls keyboard-reachable.
- Centered placement — dead-center on mobile; horizontally centered and slightly above center on desktop (stable under window resizing).
- Critical alerts look critical: red accents and an alert icon for destructive/urgent confirmations, so habituated users don't dismiss on autopilot.
The context-dependent decisions (surface, don't auto-apply)
| Decision | Apply when | Avoid / adapt when | Default recommendation |
|---|---|---|---|
| Popup modal | The standard high-stakes interrupt over dimmed content | Content that needs a whole page | Default modal type |
| Fullscreen modal | Complex focused tasks: multi-step forms, payments, T&Cs, mobile spotlight moments | Simple confirmations (overkill); anything users may need to escape fast — make dismissal obvious | Only when the task genuinely fills a screen |
| Popover | Extra detail/options anchored to an element, without blocking the page | Critical information (too easy to miss) | The non-modal default for contextual help |
| Lightbox | Image/video magnification with navigation, captions, zoom | Non-media content | Media-rich products only |
| Bottom / action sheet (mobile) | Lists of related actions or share targets, per OS convention | Critical confirmations (use an alert/dialog) | Android bottom sheet / iOS action sheet for action lists |
| Success feedback | Inline or on-page states | Success modals — interrupting to say "it worked" | Modal success only if users must acknowledge before continuing |
| Permission requests | In context, at the moment the feature needs it; primed with a pre-permission explainer; one permission at a time; a compelling reason (+81% grant likelihood) | At first launch, in batches, with "Recommended" pressure labels, or mid-task | Prime → contextual ask → graceful path to reverse a denial |
| System-initiated modals | Truly urgent: session expiry, security, data loss | Subscription nags, timed promos, rating begs | Almost never; use banners/badges instead |
Validate the result (orchestration)
Hand-offs name each lens by its installable skill
name. Invoke one only if that skill is installed; if it isn't, this skill's own core already carries these rules — proceed without it rather than blocking.
After generating or revising, hand the result to the audit lenses rather than declaring it done. These are candidate lenses — posture is set by docs/orchestration-policy.md, or route the whole thing through ux-design-review. Here, heuristics, microcopy, and dark-patterns are Tier A (auto-run); accessibility, aesthetics, and mobile-responsiveness are Tier B (offered) — under an existing design system aesthetics is suppressed and accessibility narrows to usage; mobile-responsiveness applies only on mobile. If the user invoked this skill for one specific thing, respect that scope.
ux-heuristics-audit(Tier A) — user control and freedom (exits), error prevention (explicit confirmations), match to expectations (platform conventions).ux-accessibility-audit(Tier B — offer; narrow under a design system) — focus trap correctness, keyboard dismissal, screen-reader announcement, contrast of overlay content.ux-aesthetics-audit(Tier B — offer; suppress under a design system) — modal visual hierarchy, overlay treatment, alert-styling restraint.ux-microcopy-audit(Tier A) — title clarity, button explicitness, body brevity, permission-reason wording.ux-dark-patterns-audit(Tier A) — this skill's interruptions are prime dark-pattern territory: nagging system modals, shame opt-outs, permission pressure, hard-to-find dismissal.ux-mobile-responsiveness-audit(Tier B — offer; applies only on mobile) — when the context is mobile: sheet conventions, dismissal gestures, fullscreen behavior.
If the audits surface a conflict (e.g., growth wants a signup modal on page load vs. user control), resolve back toward the primary task: the user was doing something — the modal must either protect that task or get out of its way.
Common do/don't patterns
| ❌ Don't | ✅ Do |
|---|---|
| Modal for a success message or a tip | Inline state / toast; modals for high-stakes only |
| Timed subscription popup mid-reading | User-initiated modals; system interrupts only for urgency |
| "Are you sure?" → Yes / No | "Discard draft?" → "Discard" / "Keep editing" |
| Three+ buttons including "Learn more" | Two actions, aligned to the title |
| No × , no Esc, no outside click | Close button + Esc/Back + outside click (when safe) |
| Modal opens on top of another modal | One modal at a time, ever |
| Vital info buried in body text | The title carries the message |
| Permission batch on first launch | Primed, contextual, one-at-a-time requests with reasons |
| "No thanks, I like missing out" | Neutral, respectful opt-out labels |
| Focus stays on the page behind | Focus moves into the modal, onto the primary action |
| Ship without checking | Hand off to heuristics + accessibility + aesthetics + microcopy + dark-patterns |