Bonus Terms at 6 pt: Comprehension Drops 31% in 500 Tests

A controlled trial of 500 participants found that setting bonus terms in 6-point type reduced accurate comprehension of key conditions by 31% relative to the same text set at 11 points. The effect held across age bands and was largest for wagering multipliers and maximum cashout caps — the two clauses players most often cite when disputing a payout. The study, run across four English-speaking markets in early 2024, suggests that legibility is not a cosmetic issue but a functional one: terms a player cannot read at a glance are, for practical purposes, terms the player did not receive.

What the trial actually measured

Participants were recruited through a panel screened for prior online casino or sportsbook activity within the past 12 months (n=500; 58% male, median age 34). Each was shown a mock welcome offer — 100% up to €200, 35x wagering on bonus funds, 7-day expiry, max bet €5, max cashout €500 — rendered in one of five type sizes: 6, 8, 9, 11, and 14 points. The 6-point condition is not hypothetical. It corresponds to the fine print on several operator landing pages sampled in the same period, where the terms block occupied under 4% of the visible viewport on a standard 1080p desktop.

Comprehension was tested with eight multiple-choice items: wagering base (bonus only vs. bonus plus deposit), expiry window, max bet during playthrough, cashout ceiling, game weighting, eligibility restrictions, and two distractor items. A correct response required selecting the right option, not merely recognising a plausible one.

At 11 points, mean accuracy was 74.2%. At 6 points, it fell to 51.2% — a 23-point absolute drop, or 31% relative to the 11-point baseline. The 8-point and 9-point conditions sat between, at 64.1% and 68.9% respectively, producing a roughly monotonic curve. The 14-point condition added little over 11 points (76.0%), which suggests the comprehension loss is driven by compression below a legibility threshold rather than by linear gain from ever-larger type.

Where the losses concentrated

The aggregate figure understates the problem for specific clauses. Broken down by item:

Wagering base and cashout ceiling — the two clauses with the most direct financial consequence — showed the steepest declines. That ordering is not random. Both require the reader to hold a conditional in mind ("the bonus is released only if…") rather than retrieve a single number, and small type appears to impair that kind of processing more than simple recall.

Why this is a regulatory question, not a design one

Most licensing regimes already require that material terms be "clear," "prominent," or "easily accessible." The UK Gambling Commission's consumer protection rules, the Malta Gaming Authority's player-protection directives, and several US state frameworks use variants of this language. None specifies a minimum type size or a measurable comprehension standard. The result is a compliance test that operators can satisfy by placing terms in a scrollable modal — technically accessible, practically unread.

The 31% figure matters because it converts a qualitative standard into a quantitative one. If a regulator's intent is that the median player understands the wagering base, then a 6-point rendering fails that intent by a wide margin even when the text is present, legible in the literal sense, and legally disclosed. The disclosure happened; the communication did not.

There is a second-order effect worth flagging. Comprehension scores at 6 points clustered near chance for the cashout item (four options, so ~25% by guessing). Participants who did not understand the cashout cap were also more likely to overestimate their expected value from the offer — a mean estimate of €164 versus €118 among those who read it correctly at 11 points. Misreading fine print does not just produce confusion; it produces inflated expectations that later surface as complaints, chargebacks, and in some jurisdictions formal disputes.

The mobile dimension

The trial was run on desktop. A follow-up arm (n=120) on 6.1-inch smartphone screens found that 6-point text rendered at typical zoom required pinch-and-scroll for 71% of participants, and 44% abandoned the terms block before reaching the cashout clause. The comprehension gap on mobile was wider than on desktop, though the sample is too small to put a precise number on it. Given that the majority of casino and sportsbook traffic in most regulated markets now originates on mobile, the desktop figures likely understate the real-world deficit.

Counterarguments and their limits

Three objections are worth taking seriously.

Self-selection. Participants were panel members, not live customers mid-session. They had no money at stake and no incentive to skim. One could argue that real players, motivated by a genuine bonus, read more carefully. The counter is that real players also read faster, under time pressure, and often on a phone while doing something else. Lab conditions here probably flatter the real-world numbers, not the reverse.

Comprehension is not the same as behaviour. A player who fails the quiz might still avoid the trap by asking support, reading a forum, or simply not chasing the bonus. True. But the trial measured the thing regulators actually claim to care about — informed consent to terms — and found it absent at 6 points.

Type size is a proxy. The real variables are contrast, line spacing, font, and viewport. The study controlled for font and contrast, varying only size, which isolates the variable but also means the 31% figure is specific to that combination. A different typeface at 6 points might perform slightly better or worse. The magnitude is the finding; the exact percentage is contingent.

What a workable standard might look like

If the goal is comprehension rather than disclosure, the policy lever is a measurable floor. A minimum type size — say, 9 points or its CSS equivalent — would close roughly half the gap identified here, based on the 68.9% accuracy at that size. A stronger measure would require that wagering base and cashout cap appear above the fold, in the same type size as the headline offer, before any deposit is made. That is a design constraint, not a legal one, and it is enforceable by screenshot.

The open question is whether the industry will treat this as a compliance cost or a retention tool. Players who understand terms dispute them less. The 31% figure is a measure of how much misunderstanding the current default produces — and whether that misunderstanding is a bug or, for some operators, a feature. Regulators in at least two jurisdictions have begun asking for comprehension testing as part of licence renewal. If that becomes standard, the 6-point terms block may end up being remembered as the last era in which the fine print was allowed to be fine.