Oxygen 3 — Bonus Features
Every Oxygen 3 feature laid out from ELK's own rule sheet — Oxygen Bubbles, the three Clams, the special wilds, and the X-iter buy menu.
All Features
Oxygen Bubbles & Multiplier Strike
How to Trigger
A winning symbol is cleared from a grid position, or Multiplier Strike fires before a drop.
What Happens
The first time a winner is removed from a position, an Oxygen Bubble activates there and counts as x1. Every further removal over that same bubble doubles its value — x2, x4, x8, and up. Bubbles are not affected by gravity, so they stay anchored while symbols fall through them, and in Bonus mode every bubble and its value survives from one bonus drop to the next. Multiplier Strike sidesteps the grind entirely: it can place whole clusters of bubbles complete with multipliers onto the grid before the symbols even drop, and it can fire in any symbol drop or bonus drop.
Multipliers
Starts at x1 on activation and doubles on every repeat clear of the same position. ELK publishes a 33% hit rate for the game but no Multiplier Strike frequency.
Strategy
Bubble value is a function of chain length, so the drops worth watching are the ones that keep refilling. In Bonus mode the bubbles persist across drops, which is why the deep multipliers live there rather than in base play.
| Start | x1 on activation |
| Growth | Doubles per repeat clear |
| Gravity | Bubbles stay put |
| In Bonus mode | Persist across drops |
| Hit rate | 33% of drops |
The Clam — Pearl, Squid, Starfish
How to Trigger
The Clam symbol is a Wild. If it forms part of a winning cluster it opens straight after win evaluation.
What Happens
One of three things happens. The Pearl picks a single payout symbol, makes every copy of it sticky along with any feature symbols, then redrops everything else; the cycle keeps going while more of that symbol or more Wilds land, and ends with a full win evaluation. The Squid generates a Wild on its own square, moves to a new square and does it again, repeating until it leaves the grid. The Starfish rotates to face a horizontal, vertical or diagonal line, strips the payout symbols along it, activates any feature symbols in the path, raises the multiplier at its final position, and loops until it turns into a Wild.
Multipliers
Only the Starfish touches multiplier values directly — it raises one at the end of each pass. ELK publishes no trigger rate for the Clam.
Strategy
Squid and Starfish both feed the bubble chain, one with Wilds and one by clearing cells. Pearl is the slow burner — a long redrop cycle can resolve into a single enormous cluster.
| Types | 3 (Pearl, Squid, Starfish) |
| Clam itself | Also a Wild |
| Pearl | Sticky symbol + redrops |
| Squid | Plants Wilds, then moves |
| Guaranteed at | 25x (Clam Chowder) |
Special Wilds & Big Symbols
How to Trigger
An Exploding or Blaster Wild lands in a winning cluster, or is caught by another blast.
What Happens
The Exploding Wild waits until no more winning combinations appear, then removes every payout symbol inside two cone-shaped areas — either up and down, or left and right — forcing a refill. The Blaster Wild converts payout symbols in a Plus or X pattern into identical symbols; anything hit by a second blast becomes a Wild instead. Both can be set off by each other, by a Starfish, and by their own kind, so one landing can chain into several. Separately, symbols of size 2×2, 3×3 and 4×4 may appear in any drop, and each counts as all the 1×1 cells it covers when a cluster is measured.
Multipliers
These Wilds carry no multiplier of their own, and ELK publishes no landing rate for them. Every cell they clear is a cell that can activate or double an Oxygen Bubble.
Strategy
Their real job is feeding bubbles. A blast mid-chain clears positions that the next drop can then double, which is worth more than the immediate win it creates.
| Exploding Wild | Two cone-shaped clears |
| Blaster Wild | Plus or X conversion |
| Second blast | Converts to Wild |
| Big symbols | 2×2, 3×3, 4×4 |
| Counted as | Every 1×1 cell covered |
Bonus Game, Super Bonus & X-iter
How to Trigger
3 Bonus symbols open the Bonus game. If one of them is a Super Bonus symbol, the Super Bonus opens instead.
What Happens
Both run 10 bonus drops. The Bonus game adds an Oxygen Meter that fills on every winning combination and, once full, empties and upgrades a cluster of multipliers on the grid. The Super Bonus swaps it for the Super Oxygen Meter, which upgrades a larger cluster. Meter levels and bubble values both persist between bonus drops. Retriggers are built in: two Bonus symbols inside the feature add 3 drops, three add 5. The round ends when the drops run out or the 25,000x cap is hit, whichever comes first.
Multipliers
Meter completions upgrade whole clusters of Oxygen Bubbles rather than applying a flat multiplier. ELK states the theoretical return for every X-iter mode is the same 96.0% as base play, and publishes no trigger frequency.
Strategy
The 25,000x number is a Super Bonus number — persistence across ten drops is what lets bubbles compound that far. The 2.5x and 5x hunts don't raise the ceiling, they just shorten the wait.
| Trigger | 3 Bonus symbols |
| Drops | 10 |
| Retrigger | 2 symbols +3, 3 symbols +5 |
| X-iter tiers | 2.5x / 5x / 25x / 100x / 250x |
| Max win | 25,000x (round ends) |
Buy Feature Options
| Option | Cost | RTP | Risk |
|---|---|---|---|
| Bonus Hunt (X-iter) | 2.5x | 96.0% | One round, 3x+ trigger chance |
| Mega Hunt (X-iter) | 5x | 96.0% | One round, 6x+ trigger chance |
| Clam Chowder (X-iter) | 25x | 96.0% | One drop, 3 guaranteed Clams |
| Bonus Game (X-iter) | 100x | 96.0% | 10 bonus drops, Oxygen Meter |
| Super Bonus (X-iter) | 250x | 96.0% | 10 bonus drops, Super Oxygen Meter |
Trigger Probabilities
Base Game
Win Milestones
Try the Features in Demo
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