What is "slippage"

Slippage will figure into your final trading costs, alongside other costs such as spreads, fees, and commissions.

In our Dapp, this is available only on original router buy / sell. This is useful to avoid high buy / sell tax and also to avoid sandwitch bots.

The default is 0.3, so you have to set it manually for tax tokens, or buying on a launch with high buy tax etc