When you press on this button, you get into research menu. Bonuses may be opened and closed.
Open bonuses are lightened, the rest display in grey. If the bonus isn’t opened yet, it displays information what characteristics it will have at the moment of opening (basic) and resources required for opening.
For research experience, gold and silver may be required.
Button “Development” is always lightened and available unless bonus achieved its maximum level. If maximum level is achieved it changes to the icon “Maximum!”.
