1. Math - Build equations are complex enough that may require you to calculate breakpoints but not brain busting. These breakpoints give item choices real meaning
2. Math part two - Experience equations, diminishing returns, ias calculations that are so complex that in some cases third party calculations are required, monster level, area level, (i could go on and on) add levels of knowledge that add an awesome dimension to the game i have not experienced in other games
3. Simplicity despite complexity - simple skill system with synergies - not complicated to grasp but with clever gear choices endless possibilities of builds - Do you think developers build into the game melee sorc? or was it guess a build made viable by the genius skill, synergy and item working in tandem
4. GRIND - now in modern times grinding means gather materials to craft and reroll or improve easy to find items. Diablo offers a real grind with RNG a factor but also farming locations, methods and strategy. Real elation when shako drop or a Jah - ladder players know the first HR of a season almost makes you jump out the chair - or that first teir 85 item on SP
5. game play - two skills - right and left click. In theory its simple (fair more simple than modern day equivalents ) yet understanding DESYNC, weapon switching, Skill mapping means a great deal of skill is needed in PVP Scenarios , and even PVM, Simple for causal baal running and as complex as you want for other areas
6. Buffing - rotation style action rpg buffing is gay - remembering to press a button every 30 secs or 120 sec cool down - well d2 has item based buffing - why don't other games follow suit?
7. community - trading, friends list, simple chat commands in game, game searching, chat clear and easy in game - all perfection!
9. items - magic items, rare, unique, runewords all have a place in endgame builds. Cubing/ upgrading is genius and no crafting systems in other games have come close
10. time - Areas clear speeds not too high in endgame, gameplay in endgame fast, slow early game - well balanced - you don't need to put in 1000 hours in endgame, but it will make your char closer to perfect and have a few better stats. not a massive penalty for players lower level - Lvl 80 chars well geared not as disadvantaged as 99 char same gear. most games now need you to obtain a max level (albeit a lot easier than d2) for endgame.
your thoughts please