Gambling despite financial loss-the role of losses disguised as wins in multi-line slots.

BACKGROUND AND AIMS: Slot machines pose serious problems for a subset of gamblers. On multi-line slots, many small credit returns are less than one's spin wager, resulting in a net loss to the player. These outcomes are called 'losses disguised as wins' (LDWs). We aimed to show that different proportions of LDWs could differentially affect gambling persistence (continuing to gamble despite financial loss), but that such LDW effects may depend on problem gambling symptomatology.

DESIGN: Gamblers were randomized to play 100 spins on a game with few, moderate or many LDWs (between-subjects design), then continued playing for as long as they wished during (unbeknown to players) a losing streak (to measure gambling persistence).

SETTING: A custom-built casino in a gambling research laboratory in Waterloo, Canada.

PARTICIPANTS: Experienced gamblers (n = 132) with varying levels of problem gambling symptomatology from the Waterloo, Canada community.

MEASUREMENTS: We measured the number of voluntary spins participants played (persistence) during the losing streak following the 100-spin playing sessions. We measured problem gambling symptomatology using the Problem Gambling Severity Index, and classified them as non-problem (n = 53), low-risk (n = 55) or higher-risk (n = 24) gamblers.

FINDINGS: Persistence trends differed depending on LDW frequency and problem-gambling status (interaction: P = 0.037). High-risk gamblers showed a 'sweet spot' for LDW reinforcement, persisting for longer in the moderate than few or many LDW games (quadratic trend across LDW games: P = 0.028). Non-problem gamblers showed a linear trend across LDW games, gambling for longer in the few LDW game (P = 0.007). For low-risk gamblers, the quadratic contrast was not significant, P = 0.032.

CONCLUSIONS: Multi-line slots contain outcomes in which one gains less than the original wager (losses disguised as wins or LDWs). Moderate (versus few and high) proportions of LDWs appear to make higher-risk players gamble for longer despite financial loss.