Polkadot

Network Architecture

• Relay Chain is the main chain — coordinates security and consensus
• Parachains are independent chains — connected to Relay Chain for security
• DOT is the native token — used for staking, governance, and parachain bonds
• Kusama is the canary network — experimental, real value, faster upgrades

Address Format

• Addresses are different per network — same seed gives different addresses on Polkadot vs Kusama
• Polkadot addresses start with "1" — Kusama starts with capital letters
• SS58 format — different from Ethereum's hex addresses
• One seed for all Substrate chains — but displayed address differs per chain

DOT Token

• Redenominated 100x in 2020 — old 1 DOT = new 100 DOT
• 10 decimals (planck is smallest unit) — different from 18 decimals on Ethereum
• Existential deposit: 1 DOT minimum — accounts below this are reaped (deleted)
• Locked DOT still counts for governance — can vote while staking

Staking (Nomination)

• Nominate up to 16 validators — your stake backs their validation
• Minimum to earn rewards varies — currently around 250 DOT due to competition
• 28-day unbonding period — funds locked during unstaking
• Slashing risk exists — bad validators can lose portion of stake
• Rewards claimed manually or auto-compound — depends on wallet

Staking Pools

• Minimum 1 DOT to join pool — lower barrier than direct nomination
• Pool operator manages validator selection — less control, more convenience
• Rewards distributed by pool — minus pool commission
• Same unbonding period applies — 28 days to unstake

Governance

• OpenGov system — proposals, referenda, voting
• Conviction voting — lock tokens longer for more voting power
• Anyone can submit proposals — DOT holders vote
• Treasury funds ecosystem development — community-controlled spending

Parachains

• Parachain slots won via auctions — projects bid DOT
• Crowdloans let users contribute DOT — locked for lease period (2 years)
• Contributed DOT returned after lease — plus project tokens as reward
• System parachains have permanent slots — Statemint, Bridge Hub

Cross-Chain (XCM)

• XCM is cross-consensus messaging — transfer assets between parachains
• Teleport vs Reserve transfer — different trust models
• Not all parachains support all assets — check compatibility
• Fees paid in DOT or parachain token — depends on route

Wallets

• Polkadot.js is power-user wallet — full features, complex UI
• Nova Wallet, Talisman — better UX for most users
• Ledger support — via compatible wallets
• SubWallet for mobile — good mobile experience

Common Issues

• "Existential deposit" error — balance would go below 1 DOT, add more or send all
• Staking not earning — below minimum active stake threshold
• Can't transfer while staking — must leave some unlocked for fees
• Wrong network address — Kusama address won't work on Polkadot
• Unbonding takes 28 days — patience required

Transaction Characteristics

• Transactions finalize in ~12 seconds — deterministic finality
• Fees in DOT — relatively low, paid from transferable balance
• Nonce-based like Ethereum — transactions processed in order
• Tips for priority — optional, not usually needed

Security

• Seed phrase controls all Substrate chains — secure it carefully
• Verify addresses match network — different display per chain
• Check validator reputation before nominating — slashing affects you
• Governance attacks possible — vote on important proposals