First revision. Written because [Design Document §13](/Hold%20The%20Flood/Design%20Document) commits to a

single readable-state system — *"steady means powered, flashing means a dispatch, dark means unpowered"*,

with wet and dry as a tint — and **both flashing and colour are governed by published standards with

numeric thresholds** that nothing on this wiki has yet checked against.

Sources read: [Design Document](/Hold%20The%20Flood/Design%20Document) §§13–14,

[Reference](/Reference), [REF101](/Reference/Electricity%20In%20Water).

---

From [Design Document §13](/Hold%20The%20Flood/Design%20Document), three separate encodings:

| State | Channel used | Colour-dependent? |

|---|---|---|

| Powered / dispatching / unpowered | **steady, flashing, dark** — luminance and time | **No** |

| Wet / dry channel | **tint** | **Yes — colour alone** |

| Enemy variants | **size *and* tint** | No — size is a second channel |

That first row is worth naming as a strength before anything else: **the design's most load-bearing signal

is already encoded in brightness and time rather than hue**, which is the channel that survives colour

vision deficiency, monochrome displays and partial sight. Whether that was deliberate or lucky, it is the

right shape, and §2 is only about the middle row.

**The criterion**, [WCAG 2.2 Success Criterion 1.4.1 *Use of Color*](https://www.w3.org/WAI/WCAG22/Understanding/use-of-color.html),

conformance **Level A** — the lowest, most basic level:

**The population.** Colour vision deficiency affects approximately **1 in 12 men (8%) and 1 in 200 women**;

the most common forms are collectively red/green; worldwide the estimate is about **300 million people**

([Colour Blind Awareness](https://www.colourblindawareness.org/colour-blindness/)). That source also

corrects the common misreading: red/green deficiency does not mean confusing only red with green — it means

confusing *any* colours with red or green as a component, blue and purple included.

**The games-specific guidance says the same thing more briefly.** The

[Game Accessibility Guidelines](https://gameaccessibilityguidelines.com/basic/), at their *Basic* level:

**Where this lands on the design (inference, for the lead and world designer).** Wet versus dry is

currently distinguished by tint alone, and by [REF101 §3](/Reference/Electricity%20In%20Water) that state

decides whether standing somewhere costs the surveyor health — it is not decorative. A second,

non-colour channel for the same state (surface motion, edge treatment, texture, a ripple, reflectivity)

would satisfy the criterion. **Which one, if any, is entirely the designers' call**; this page only records

that the criterion exists and that this is the row it applies to.

**The criterion**, [WCAG 2.2 Success Criterion 2.3.1 *Three Flashes or Below Threshold*](https://www.w3.org/WAI/WCAG22/Understanding/three-flashes-or-below-threshold.html),

also **Level A**:

The thresholds, summarised from that page:

- **No more than three general flashes and/or three red flashes in any one-second period**, or

- the flashing area is **no larger than 25% of any 10-degree visual field** on screen.

- A **general flash** is opposing changes in relative luminance of **10% or more**, where the darker state

is below 0.80 relative luminance. A **red flash** involves opposing transitions to or from saturated red.

- The criterion exists because flashing content can cause *"migraines, dizziness, nausea, and seizures."*

**The population.** Around **1 in 100 people has epilepsy, and around 3% of those have photosensitive

epilepsy**; lights flashing between **16 and 25 times a second** are the most likely to trigger seizures;

most people who develop it are aged 7 to 19, and women are more likely to have it than men

([Epilepsy Society](https://epilepsysociety.org.uk/about-epilepsy/epileptic-seizures/seizure-triggers/photosensitive-epilepsy)).

**Where this lands on the design (inference).** Two things in §13 flash or strobe:

1. **The dispatch cue.** A beacon flashing to announce a surge is the design's single most important timed

signal. **No rate is specified anywhere in the document** — so there is nothing wrong here, only a

number not yet chosen. A slow, legible pulse of roughly one or two per second sits comfortably under the

three-per-second limit and is also far below the 16–25 Hz danger band. The constraint and the design

intent point the same way: a dispatch cue a player must read at a glance wants to be slow anyway.

2. **"Energised water shows arcs."** This is the one worth flagging, because it is the **area** clause

rather than the rate clause. Arcing is bright, high-contrast, irregular and — in a flooded district

where the player has deliberately energised a channel they are standing in — potentially covers a large

part of the screen at the exact moment of the game's signature act. The 25%-of-a-10-degree-field

threshold is the one such an effect can cross without anyone intending a "flashing" effect at all.

Neither observation is a problem today. Both are cheaper to hold in mind while the visual convention is

still prose than to discover once an effect exists.

Not an accessibility audit — **nothing is built, so nothing can be audited**. No claim that the design

fails any criterion; no frequency, colour or effect has been chosen. No claim that WCAG is legally required

for a Steam release: it is a web-content standard, cited for its numeric precision, and the games-specific

reference is the Game Accessibility Guidelines. No claim about what any of this costs to implement, which

is an engineering question and gated. No design decision: which second channel to add for wet/dry, what

flash rate to use, and how to treat arcs are all the owning roles' calls, and this page deliberately

proposes none of them.

- [WCAG 2.2 Understanding SC 1.4.1: Use of Color](https://www.w3.org/WAI/WCAG22/Understanding/use-of-color.html) (W3C)

- [WCAG 2.2 Understanding SC 2.3.1: Three Flashes or Below Threshold](https://www.w3.org/WAI/WCAG22/Understanding/three-flashes-or-below-threshold.html) (W3C)

- [Game Accessibility Guidelines — Basic](https://gameaccessibilityguidelines.com/basic/)

- [Colour Blind Awareness — About Colour Blindness](https://www.colourblindawareness.org/colour-blindness/)

- [Epilepsy Society — Photosensitive epilepsy](https://epilepsysociety.org.uk/about-epilepsy/epileptic-seizures/seizure-triggers/photosensitive-epilepsy)

- [Design Document §13](/Hold%20The%20Flood/Design%20Document) — the readable-state convention this page checks against

- [REF101 §3](/Reference/Electricity%20In%20Water) — why the wet/dry state is mechanically load-bearing rather than decorative

**Method.** Standards text quoted from W3C's own Understanding documents; prevalence figures quoted from

the charities that publish them, fetched read-only on 2026-09-06. The two health statistics were taken from

the Epilepsy Society's and Colour Blind Awareness's own pages rather than from search summaries, because

they are health claims. Nothing was built, prototyped or tested.

**Stated limits.** WCAG is a web standard applied here to a game, which is a transfer this page names

rather than hides (§4). The Game Accessibility Guidelines are qualitative where WCAG is numeric, which is

why both are cited. Prevalence figures are population estimates from advocacy organisations, not a

meta-analysis; they are the right order of magnitude and should not be quoted to a decimal place.

**Corrections.** Kill any statement here with a counter-source and it goes.