I have no quake C skill at all which is why I'll be needing a lot of support from you the beloved Nexuiz community if this is to become a reality.
Gameplay
The map will be divided into 2 bases (like CTF) and players divided into 2 teams (like CTF).
Each base will be guarded by stationary, destructible turrets. At the heart of each base is the team's ancient which the team must defend.
To assist each team, bots automatically spawn at their ancient and mindlessly runs towed the enemy ancient, attempting to destroy all resistance. These bots would typically be killed quite quickly.
As bots die they drop money and increase the level of enemy players.
As players level increase their hitpoints, damage, healing rate and movement speed improve.
Each character has a different model and starting weapon set based on selected class and level. Other weapons and items can be bought with accumulated money. Various Items will be available to improve hitpoints, damage, healing rate, movement speed, provide temporary invisibility, or modify purchased weapons into superweapons.
The gameplay will be considerably slowed as compared to Nexuiz Deathmatch. The focus should shift from getting lots of kills to surviving and leveling up.
The game ends when one team's base is overwhelmed and their ancient destroyed.
Plan
The mod is quite a significant coding undertaking so i have broken up the task into some simple, achievable goals which will be discussed in subsequent posts as this one is already pretty long.
The Nex-Life mod from way back showed that a currency reward system can work in game. Maybe you should see if you can track down the source to that for a little help in the coding process?
