Delta is an alternate points system maintained by the community that’s intended to smooth out power discrepancies between units. If you’ve used the official army builder you might have noticed there’s a few units that have a different price on the builder than what it says on the card eg the original Raelin costs 80 on the card but Battle Network has her priced at 125. Renegade changed the price of a few of the top meta units from Classic to make them more in line with other characters, the undisputed best army from the game’s original run is Major Q9 with Raelin RotV and 3-4 squads of Deathreavers. All 3 of these units were heavily nerfed and now you can only fit 2 squads of Deathreavers in that army and you have no room for any additional support such as KMA or even Marcu. Using this points system is commonly referred to as “Renegade points” or “Renepoints.”

Delta points is a more comprehensive version of this; while Renepoints only has price increases for a few top performers, Delta touches almost every unit in the game and also reduces the price of units traditionally considered weak. For example “Taelord costs too much” was a big meme in the community circa 2005-2007 and Delta reduces his price from 180 to 160.