Spellforce 1 and its two expansions are solid and definitely worth playing, although the graphics are pretty dated (Spellforce: Order of Dawn is the base game, Breath of Winter is the first expansion, and Shadow of the Phoenix is the second expansion). Some gameplay elements are also a little janky, and AI deficiencies easily exploited. Spellforce 2: Shadow Wars and its first expansion, Dragon Wars, are also worth playing; formula is pretty much the same as the first game, with updated graphics and some small gameplay upgrades. Storytelling and writing took a bit of a hit, though, and can be a bit cringe at times (not that story or writing were a particular selling point on the first game, mind you). The second two expansions for Spellforce 2, Faith in Destiny and Demons of the Past, are hot garbage and should be avoided. Spellforce 3 is still the same general formula as the first two games, but once again with greatly updated graphics and gameplay updates. Spellforce 3 and its two expansions (Soul Harvest and Fallen God) are all solid and worth a play. While within each game + expansions series its recommended to play the base game and expansions in order, you can jump in at either Spellforce 1, 2, or 3 and not really miss anything around gameplay tricks, story, or lore, so just pick whichever of the three looks most appealing to you.