Mercy Marathon
Merciless points race to 500. Free in your browser, no download.
About Mercy Marathon
Mercy Marathon: Merciless points race to 500. Extreme tables add one of the three rule packs — Merciless, Eclipse or Eruption — or throw all of them at once.
The table
4 players: you and 3 computer rivals. Everyone starts with 7 cards.
Sharp rivals shed high-value cards first, save their wilds for the end and keep the colour they hold most of alive. They are the standard opponent.
The deck
The table uses the 126-card Prism deck: numbers 0–9 in four energies (Flare ▲, Surge ●, Volt ◆, Void ■), two each of FLIP, FREEZE, +2, SHIELD and SWAP per energy, 6 PRISM wilds and 4 +4 wilds.
The Merciless pack adds +6, PURGE and FREEZE ALL in every energy, plus wild +10, REV +4 and ROULETTE cards.
How a turn works
On your turn, play one card that matches the active energy (colour) or the symbol of the top card. Wild cards play on anything and you choose the next energy.
Can't play? Draw one card and your turn passes.
Special rules at this table
- Stacking with cross-stacking: answer any +2 or +4 with another draw card — including a +4 on a +2 — and the whole pile moves on to the next player.
- SHIELD cards stay in front of you and block the next draw attack aimed at you, however big it is.
- The Riot Meter charges with every card you play; combos charge it faster. At 100% hit RIOT BURST to shatter up to 2 number cards of the active energy at once.
- Mercy rule: reach 25 cards in hand and you are knocked out of the round. The last player standing wins if nobody sheds first.
How to win
This is a points race to 500. Each round, whoever sheds their hand first scores the points still held by everyone else — numbers at face value, actions 20, Merciless actions 30, wilds 50 (+10 is 60). Rounds keep coming until someone reaches 500.
Tips for Mercy Marathon
- Keep your hand small. With the mercy rule a single +10 on a big hand can knock you out — PURGE and FREEZE ALL are your escape hatches.
- Charge the meter with combos. Several plays in a row fill it faster; burst when it shatters your highest-point number cards.
- Play a SHIELD early when your hand is large — it waits in front of you and eats the next +4 or +10.
- This mode trains consistency on your skill radar and pays ×1.8 XP.
Rule guides for this mode
Frequently asked questions
Is Mercy Marathon free to play?
Yes. Mercy Marathon and every other Prism Riot mode are free in your browser with no download, no sign-up and no account. Progress is saved in your browser.
Can I play Mercy Marathon offline?
Yes. After your first visit Prism Riot works offline — add it to your home screen from the browser menu and it opens like an app.
How many players are in Mercy Marathon?
4 players: you against 3 computer opponents at sharp difficulty. Each starts with 7 cards.
Can you stack draw cards?
Yes — +2 on +2, +4 on +4 and, at this table, +4 on +2 as well. The pile keeps growing until someone can't answer.
Can I challenge a friend on the same deal?
Yes. After a round, tap “Challenge a friend” — the link opens the exact same shuffle for them, with your score to beat.