How does symbol upgrade frequency from Heart of Golem affect long-term RTP?

Detailed Explanation

The symbol upgrade frequency from the Heart of Golem in Tome of Madness directly boosts long-term RTP by transforming low-value symbols into higher-paying ones, increasing average payouts per cluster win and contributing to the game's overall 96.59% RTP.

This Play'n GO slot uses a 5x5 grid with cluster pays mechanics, where the Heart of Golem feature activates via the Portal Meter. Every winning cluster fills the meter, triggering upgrades after 12 symbols collected—upgrading the lowest symbol to the next tier (e.g., from basic relics to Rich Wilde or eldritch horrors). This happens frequently in extended base game sessions due to cascading wins, with upgrades persisting until the grid clears, amplifying multipliers and wild spreads.

Over millions of spins, these upgrades elevate payout potential, countering the high volatility while capping max wins at 2,000x your stake. Note RTP can vary (down to 94.52% at some casinos), so check game info before playing.

Practical tips for players:

• Start with 0.10 to 100 bets to build the Portal Meter patiently during base play.
• Aim for full upgrades before entering Other World Free Rounds, where Mega Wilds like Cthulhu can explode wins up to 2,000x.
• Play at casinos offering the full 96.59% RTP version for optimal long-term returns—expect dry spells but chase cluster chains for upgrades.