Symbol Upgrade Symbol Upgrade

Overview

Symbol Upgrade is a feature that changes symbols or cells into a higher tier during play. A low-paying symbol becomes a high-paying one, a wild becomes a bigger and stronger wild, or the prize tier of a cell goes up. An upgrade often lasts until the end of the bonus, so it is commonly used to build wins that grow toward the later part of free spins.

The types of symbols themselves are covered in slot symbol types, and features that stay until the bonus ends are covered in a separate entry. This article looks at what gets upgraded and under what conditions, using game examples.

What can be upgraded

Conditions that trigger an upgrade

Random

Habanero’s Bikini Island Deluxe highlights “random symbol upgrades” as a special feature. It says any symbol can change into a higher-paying version.

When a special symbol lands

In Pragmatic Play’s Coven Rising, a modifier symbol that lands in the middle cells of the grid raises the value of regular symbols. Upgrades created by modifiers in free spins last until the end of the round. In Lucky Tiger Gold, a coin symbol during respins gives one of the following: an extra life, a multiplier increase, or a symbol upgrade.

When a higher win lands

In ELK Studios’ Respin Circus, respins start with a payline win of 3 or more matching symbols, and that symbol becomes locked. If a higher-paying symbol wins during the respins, the whole locked group upgrades to that symbol.

When a collection meter fills

In NetEnt’s Jack and the Beanstalk, you collect keys on reel 5 during free spins. With 3 keys, the wild becomes a 2-cell stack, with 6 a 3-cell stack, and with 9 an expanding wild that covers the whole reel.

When a symbol lands on the same cell again

In Brick House Bonanza, a cell where a scatter lands during free spins is marked with straw, and if one lands on the same cell again, it upgrades to wood and then to brick. When the round ends, prizes are revealed in a range of up to 1.5x for straw, 60x for wood, and 5,000x for brick. Dragon Tiger Fortunes upgrades the same way, through bronze, silver, and gold tiers.

Similar feature: removing low-paying symbols

Removing the low symbols entirely to increase the share of the remaining symbols has a similar effect to an upgrade. Habanero’s Happiest Christmas Tree removes the low-paying symbols used in a win from the next spin onward during free spins, and Pragmatic Play’s Caishen’s Gold removes low-value symbols from the reel strips during free spins.

AI Slot example games

RTP and max win are based on AI Slot game information.