Terms decoder
Game contribution is not return to player
Two percentages can appear in the same document while measuring completely different things.
Progress through a condition
A contribution rate describes how a qualifying stake counts towards a wagering requirement. In a hypothetical example, £10 staked at a 20% contribution counts as £2 of progress. A contribution rate says nothing about whether that bet will win.
Return across a model
Return to player concerns the mathematical relationship between stakes and prizes over many plays. It is not the percentage of a bet that counts towards a promotion. Treating the two as interchangeable produces incorrect calculations and can make an offer look simpler than it is.
A practical reading order
Identify the relevant amount, multiplier and contribution first. Then read excluded games, time limits and stake restrictions. If the terms are unclear, seek an explanation before accepting the promotion. There is no obligation to take a bonus, and completing a wagering requirement is never assured by the arithmetic alone.