At the top of the Pricelist module you find the button with cogwheel icon for setting the key system parameters for the price calculation.
This general setting will be used for all of your rateplans.
Pricing policy
First you select if you want to use occupancy based pricing or pricing for entire room (no matter how many guest will stay).
Setting applies for all of your rooms. It is not possible to use different pricing policies for different rooms. Of course it is possible to use occupancy based pricing and for example for double room you can set the same price for one and also two guests in the same room.
Guest categories discount
This setting is visible only in case you use occupancy based pricing and makes sense only in case you offer discount for guest categories like children, seniors, etc.
You can use one of the three possible discount calculations. Each calculation method is explained in example case in the hint at the end of the row.
Method of discounts redistribution for guest categories in room account
Easy enough, do you want to see a guest category discount as separate item in room account or you want it to be calculated in accommodation services items?
Restrictions for min/max stay length, possible arrival/departure days and min advance of reservation
All types of restrictions can be set same for all rooms (by seasons) or separately for every room type (by season and room types).
You can combine different options together. For example restrictions for length of stay can be set separately for every room type and possible arrivals/departures can be same for all room types (and vice versa).