> For the complete documentation index, see [llms.txt](https://token-tactics.gitbook.io/guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://token-tactics.gitbook.io/guide/en/how-to-play-core-mechanics.md).
# How to play: Core mechanics
### How to buy or sell cryptocurrency?
On the main Portfolio screen, tap the round blue "+" button at the bottom right 
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Then choose a cryptocurrency from the list and tap it. An additional row with an "Add" button will appear. Purchases are always made for 10% of your *available* vUSD balance.
To sell an asset, tap its tile on the main "Portfolio" screen, choose "Sell" and confirm the sale.
### What is "Level" and how do you increase it?
Level is your progress in the game. It affects how many cryptocurrencies are available to you, how many referrals you can invite, and what weekly vUSD withdrawal limit you will have.
To increase your level you need to meet two conditions:
1. Accumulate experience (XP), which is awarded for buying and selling assets at a profit.
2. Complete special tasks (for example, "sell 1 asset with a profit" or "collect 10 assets in the portfolio at the same time"). XP is also granted for completing them.
To see your current tasks, tap the blue icon with your level number in the top left corner 
### What is a "Daily streak" and why is it important?
A streak is a counter that shows how many consecutive days you have performed trading actions. For a day to count, you must **make sure to buy or sell at least one asset**.
**Important:** Simply opening the app is not enough; you must make a purchase or sale of an asset. If you skip a day, the streak resets.
**Important:** A 7-day streak is one of the mandatory conditions for participating in the weekly airdrop (exchanging vUSD for real USDT).
### Why can I only make 3 trades? When will new trades become available?
You have 3 "slots" for asset purchases. Each purchase consumes 1 slot. A new slot replenishes every 2 hours, but they cannot accumulate beyond 3.
Selling assets does not consume slots.
If you want to buy more often, you can purchase the "Monthly Pass" in the app store, which increases slots to 6, and a new slot will be added once per hour, but still cannot accumulate beyond 6 slots.
