Age of Wonders

Nice tabletop style RPG releases in 1999. The story really isn't all that great but the gameplay, artwork and everything else is really good or it was when it was released.

Players have an isometric view of the map, which consists of hexagonal tiles, and can have up to three layers (surface, caverns, and depths). Units are arranged into groups (also known as parties or stacks) of up to eight units; a single such group occupies one tile. Cities occupy between one and four tiles, and other structures generally occupy a single tile.
Each player leads a certain race. There are 12 races available in the game, though not all of them may be present on every map, and of those which are, not all may be playable. List of races includes traditional fantasy Elves, Lizardmen, Humans, Goblins, Dark Elves, Undead, Orcs, Dwarves and Halflings, as well as several unique ones such as Frostlings, Azracs, and Highmen. Races, as well as units not belonging to any specific race, such as dragons and giants, have a certain alignment, which can be good, neutral, or evil.

According to their alignment and certain other factors, cities and independent units of one race can be friendly or hostile towards another race. This can manifest itself in different ways; for example, an orc city is not likely to surrender to the elves, and if conquered, may revolt unless there is a strong military presence in it to oppress the population. Units of hostile races forced to fight alongside each other in a single group will have lower morale, and are more likely to desert. Race relations can be improved by acts of goodwill towards other races, such as upgrading their cities, or hampered by razing, looting, or migrating cities belonging to that race. Diplomacy can also affect this and even an alliance with one race might affect the relation of another race. There are also several spells which have a global effect on race relations.
There are two resources, gold and mana. Gold is used to build units, buy heroes, cities and spells (in Wizard Towers), upgrade cities. Mana is used to cast and research spells and use altars.

There is a lot to do in this game. There are a lot of hidden units, heroes and treasure on each map. IIRC you can make a lot of decisions that affect how your game plays out. And its another game that's available on GOG and STEAM.