Renkei (連携) is Japanese for 'link' or 'cooperation'. This system is heavily borrowed from the MMORPG Final Fantasy XI in which you could link various weapon techniques together to create a Renkei, or a Skillchain (as they called it in the English version). The version that I'm doing for Battle Arena is a bit more simplistic than FFXI. In FFXI you had to have the correct linking techs (not all techniques could be linked together) and had to have a specific timing down in order to make it work. Also, you could do more techniques to create better skillchains (you could link three together to create a level 3 skillchain, for example).
Because of the way mIRC works and how the battles are set up in Battle Arena, I immediately ditched the timing idea. Forcing players to do stuff within a time limit on IRC is a really bad idea (I learned that first-hand with my first Battle Bot, Kaiou). To simplify things, and make it easier for myself, I decided that all player techniques could link together--ditching the idea that only certain techniques could create skillchains. Techniques are rarely used to begin with and limiting them to linking with only other certain techniques would make the system pointless, I felt.
So here's how it's going to really work. First off, each technique will be worth a 'renkei' value. The renkei value is what determines which renkei is performed. Higher level renkeis will result in higher damage. The damage that the renkei done will be a percentage of the total damage done by the techniques to create the renkei. Two techniques are needed to create a renkei on a monster. But there's a catch to that: when it's the monster's turn, the # of techniques used on the monster, the technique damage value, and the renkei value are all reset to 0. 'But Iyou! That means I can't self-skillchain when I'm soloing on here!' Well, you can and here's how. You have two options to self-renkei now. First, you could use Sugitekai to give yourself two turns in a row then use a technique on both turns thus resulting in a renkei. The other option is via the active skill called Konzen-Ittai. This skill will double the technique number value. Basically it means that 1 technique will be counted as 2, thus allowing you to self-skillchain without needing another person or using Sugitekai.
One thing to note though is that magic, AoE, and some status-inflicting techniques will not cause a renkei to happen. Mainly this is done to help prevent the bot from flooding out (especially on AOE techniques) but also because magic and status techniques are already sort of haxx to begin with.