CasesUpgradeBattlesMissions
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Open CS2 cases, run PvP case battles, upgrade your skins on a provably fair platform.

18+Over 18 only

Games

  • Cases
  • Case Battles
  • Upgrade
  • Missions

Popular

  • SWAG Bastion
  • Hydroponic Garden
  • Exotic
  • Dream
  • Crimson Web

Information

  • Provably Fair
  • Terms of Service
  • Privacy Policy
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csmafia is a CS2 case-opening platform built around provably fair mechanics. Every case opening, battle round, and upgrade roll is generated from a publicly committed server seed, a player-controlled client seed, and a monotonically incrementing nonce — outcomes can be independently verified after the fact.

Open cases to pull skins across the rarity spectrum. Run case battles with up to four players and fifty rounds, with the highest total value taking everything. Upgrade skins by staking your inventory toward a higher-value target — odds and house edge are shown before every roll.

Skins can be sold back for instant balance, used as upgrade stakes, or set aside for case battles. Steam trade withdrawal is in development pending licensing. Balance withdrawal is crypto-only.

csmafia is for entertainment. 18+ only, or the legal age in your jurisdiction if higher. Coins and items are part of the experience and have no real-world monetary value.

© 2026 csmafia. All rights reserved.Not affiliated with Valve. CS2 and related items are property of their respective owners.

For entertainment only. 18+. Coins and items are part of the experience and have no real-world monetary value.

Provably Fair

Every case opening on csmafia is verifiable. You can prove no result was tampered with — before or after the fact.

1. Commitment

Before you open anything, the server generates a secret server seed and shows you its SHA-256 hash. The hash is a commitment — the server cannot change the seed afterwards without breaking it.

2. Your input

You get a client seed (you can set your own) and a nonce that counts up by one with every case you open. Both are fully visible to you.

3. The roll

Each opening’s outcome is HMAC-SHA256(server seed, "client seed:nonce"). The hash is turned into a number that selects the skin by weight. Same inputs always produce the same result.

4. Verification

When you rotate your seed pair, the old server seed is revealed. Hash it yourself — it must match the commitment from step 1. Re-compute every roll with the verifier — each must match what you got.

Your seeds

Sign in to see and rotate your seed pair.

Verifier

Verify a roll

Runs entirely in your browser (Web Crypto), independent of our servers. The hash it produces should match the roll recorded on your opening.