Mighty Black Knight Slot by Light & Wonder

The standout trick fires the moment a Black Knight lands. The wooden portcullis above the reels grinds upward, the knight rears into view, and the grid stretches from five rows to ten, doubling whatever line count you were playing. So a 50-line spin becomes 100 lines mid-spin, with twice the board suddenly live. The base game keeps those upper rows dark behind the grille, dimly visible as a promise of what the wild unlocks.

The Black Knight in full plate armour is that wild, and it works on a generous rule: any sliver of him peeking into view expands to fill his entire reel. You don't need the whole symbol on screen, just a corner. He stands in for everything but the Bonus, in the base game and the free spins alike. Three or more scattered Bonus symbols, again counting any part in view, hand over 8, 12 or 20 free spins depending on how many land, and you can retrigger them from inside. One quirk worth knowing: the free spins open with the portcullis down and no Mighty Reels active, even if you triggered them while the grid was expanded, so they start on the small board and rebuild from there.

There's a separate high-stake mode too, the Premium Play. Instead of a normal spin you play a little three-reel mini game on a single win line, and matching three there buys you five linked spins of the main reels. The catch that makes it tick: wilds turn persistent through those five, locking in place until they form a win, and every payout from the run is held back and settled together on the last spin. It's a heavier-commitment alternative to a bonus buy, not a shortcut to the free games.

Visually it's a torch-lit castle in rich purple and gold, the reels mounted on a stone wall between two towers with flames flickering in iron brackets. Heraldic playing-card suits fill the low end, blue spades, red hearts, pink diamonds and purple clubs, while gold rings, jewelled orbs and a sceptre climb toward red royal crowns and a veiled Queen up top. This is an older Barcrest build, now flying the Light & Wonder flag, and the Mighty Reels expansion is what keeps it from feeling like a straight card-symbol grinder.