Locked symbols remain in place during bonus features by keeping specific icons fixed in certain reel positions. These symbols do not get replaced on the following spins or respins while the feature is active. This system is commonly seen in free credit slot games where locked icons help increase winning chances. The position locking happens when special conditions are met, and selected symbols freeze while the surrounding reels spin again.
Position lock mechanics
Locking activates when specific symbols land on reels during bonus round initiations or through progressive accumulation during feature play. Games designate which symbol types qualify for locking status, commonly including money symbols, special bonus icons, or high-value premium symbols. Qualified symbols landing on reels during lock-eligible spins receive persistent status immediately upon position settlement. Visual indicators distinguish locked symbols from regular refreshing positions through frame overlays, glowing borders, chain graphics, or colour highlighting. Locked positions display identical symbols across all subsequent feature spins, while unlocked positions populate with random new symbols each round.
Feature duration persistence
Lock duration mechanics determine how long symbols maintain fixed positions before removal or feature termination, releasing persistent status through varied timing frameworks.
- Complete feature persistence – Symbols remain locked throughout the entire bonus round from activation through final awarded spin completion
- Spin-limited duration – Locks persist for predetermined spin quantities before automatic release, regardless of remaining feature spins
- Conditional removal – Specific trigger events like collection completion or meter filling release locked symbols mid-feature
- Progressive decay – Locked symbols decrease in quantity through systematic removal as features progress
Hold-and-spin implementations commonly employ complete persistence where initial locked symbols remain throughout three-spin sequences plus any resets triggered by additional symbol landings. Free spin features might maintain locks across ten, fifteen, or twenty awarded rounds.
Symbol accumulation process
Progressive locking systems build symbol collections throughout feature progression rather than establishing complete lock sets during initial activations. Each qualifying symbol landing during bonus spins adds to the existing locked collection, gradually filling available reel positions. Accumulation continues throughout the feature duration as new qualifying symbols join previously-locked positions. Games might cap maximum locked symbols at specific quantities, preventing complete grid saturation. Progressive accumulation creates escalating winning potential as locked symbol density increases throughout extended feature participation, with later feature spins benefiting from substantial accumulated locked collections established during earlier rounds.
Removal trigger conditions
Lock release mechanisms determine when persistent symbols clear from fixed positions, allowing normal symbol population resumption through specific termination events.
- Feature conclusion release – All locked symbols clear automatically when bonus rounds end, returning grids to standard configurations
- Collection completion removal – Filling all available positions with locked symbols triggers instant prize awards, followed by position clearing
- Win combination fulfilment – Achieving specific winning arrangements completes objectives, releasing all locks
- Progressive elimination – Individual locked symbols are removed sequentially through spin-by-spin decay processes
Locked symbols remain throughout bonus features via position fixing mechanisms, feature-duration persistence frameworks, progressive accumulation systems, conditional removal triggers, and attached value preservation. Persistence creates cumulative winning potential through maintained symbol presence across multiple outcome evaluations. Lock duration varies from complete feature persistence through conditional release based on specific trigger events or progressive decay patterns.
