The title is self explanatory: attacking other players for exp is not useful. 20 whole energy is not a cost to sneeze at, and even if you win the exp yield is often less than winning 1 battle in explore, which you can do in less energy.

Seeing as this feature is Lioden's main form of PvP I feel like it could be more fleshed out than a coin flip to gain a small amount of exp. Maybe the exp gained from attacking could scale like sparring does? This would make it more valuable for higher level players, who don't really bother with the system as-is. That always struck me as kind of ironic--there's a community of statters and a pvp system but unlike every other game they have nothing to do with each other.

(Note: I understand a major overhaul to gains from attacking might warrant a rebalance of the attacking system, how much energy it takes or how often you can do it, I'm asking for a tweak with 0 rebalance that breaks the game)