How to recognize it in the interface
01
The final order or plan has items that were not in your request.
Not this pattern: offering an upgrade and waiting for you to choose it.
Same moment, different copy (illustrative example)
Before
“Done. I also added priority delivery and a 12-month warranty.”
Shows the pattern
After
“Done. Priority delivery is 25 SAR extra. Add it?”
The fair alternative
Design guideline
Asks before adding anything that costs money and lists every extra.
Do
Asks before adding anything that costs money and lists every extra.
Don’t
Don’t add paid items without a clear yes.
Sources
01
Mathur et al., 2019. Dark Patterns at Scale: Findings from a Crawl of 11K Shopping Websites. CSCW 2019. arXiv:1907.07032 ↗
02
Gray et al., 2018. The Dark (Patterns) Side of UX Design. CHI 2018. doi.org ↗
03
European Union, 2011. Consumer Rights Directive 2011/83/EU, Article 22 (additional payments). eur-lex.europa.eu ↗
04
Guo et al., 2025. SusBench: An Online Benchmark for Evaluating Dark Pattern Susceptibility of Computer-Use Agents. arXiv:2510.11035 ↗
05
Tang et al., 2025. Dark Patterns Meet GUI Agents: LLM Agent Susceptibility to Manipulative Interfaces and the Role of Human Oversight. arXiv:2509.10723 ↗