On-/Off-chain
The game has be designed with a mix of on-chain and off-chain mechanisms.

On-chain

The tokens of the players are stored in their wallets (see Contracts): characters, items and gold. They can be used in game.
Character tokens store only a few fixed attributes (see note on Characters). Other attributes are computed by the game from these or stored in separate contracts (e.g. leveling system, marketplace...).

Off-chain

The game engine processes a large amount of data from the blockchain, and handles most of the game mechanisms.
The main reason is to enable more interesting gameplay, with frequent updates, and to keep the quest content secret (more things to discover!). The secondary reason is to avoid unnecessary transaction fees by reducing the number of transactions and therefore the cost to the player.

Token claim

This is why quest rewards are not sent directly to the player's wallet, but stored in the game waiting to be claimed.
Think of this as an adventurer dropping off loots in the guild leader's desk waiting for someone to deposit them in the safe.
Players have to claim their rewards (items, gold) to initiate the transaction and receive them in their wallet. This can be done at any time.