LemonArcade
Ruthless! Merciless Cards is an online multiplayer game built on the Crazy Eights family of shedding card games, the same lineage that also produced Mau Mau and, much later, Uno. No named development studio is credited anywhere beyond Playgama's own distribution listing, so unlike some games in this catalogue, the actual studio behind Ruthless! could not be verified — this is stated plainly rather than guessed at.
The base rule is the familiar one from the Eights family: play a card that matches the colour or number of the card on top of the pile, or draw if you have nothing playable. Where Ruthless! earns its name is in the penalties. Drawing is not a minor setback here, since a player who reaches 25 cards in hand is eliminated outright, which means a bad run of forced draws can end your game entirely rather than just slowing you down. That elimination threshold changes the calculus of every penalty card played against you, since even a single unlucky exchange can push a hand that was manageable into genuine danger territory.
Three house rules layered on top of that base rule give the game its identity. RUNS let you drop a whole sequence of consecutive numbers in one colour in a single turn, with the last card in the run deciding the new colour, which means a strong run can change the colour, land a penalty and empty half your hand all at once. COLD BLOOD is a single-use token per match that freezes an incoming penalty and doubles the next one you deal back. DOUBLE! raises the stakes on a hand you're winning, and opponents can fold before it lands rather than risk it. Together, the three rules push a normally low-tension shedding game toward something closer to a bluffing contest, since a player sitting on a strong RUN or holding COLD BLOOD in reserve changes how everyone else at the table plays their own cards.
Social structure matters as much as the ruleset. You can play a quick match against bots that carry some personality when no one else is around, join a Classic table that resets daily for everyone, climb a ranked Arena with leagues, team up for 2 vs 2, or run three-round tournaments and private rooms with friends. All of it runs on a 168-card deck, larger than a standard deck, built to support these various formats without running dry. That larger card pool keeps RUNS and penalty chains from drying up in longer 2 vs 2 or tournament matches.
That combination of an easy-to-learn base rule and three sharp house rules makes it a fit for players who already know Crazy Eights or Uno and want a version with real teeth, rather than a slower, more forgiving family variant. The elimination-at-25-cards rule in particular changes the emotional tone of a match: you are never just shedding cards calmly, since every penalty you take is a step toward being knocked out.
On LemonArcade it runs free in the browser, on desktop or mobile, with no download or account required. Matches move quickly once you know the house rules, usually a few minutes for a quick game and longer for ranked Arena or tournament play, and the difficulty comes less from the base Crazy Eights logic than from reading when to spend COLD BLOOD or risk a DOUBLE! against a real opponent.