Overview

Last Stand is a two-player networked FPS game implemented with the Unity game engine, specifically designed to study the impacts of latency and latency compensation techniques on player performance and QoE. The game is set in a dense jungle environment, featuring numerous tall trees, thick foliage, an open hangar at the center, and uneven terrain formations. The gameplay features rounds of deathmatch 1v1 play with unlimited lives. The player character is equipped with fluid procedural animations for actions such as sprinting, jumping, aiming, and leaning. The game equips players with a single-fire rifle that holds a customizable number (default 11) of bullets per magazine (unlimited magazines) and a customizable fire rate (default 250 rounds per minute).

A central feature of the game is the configurable experimental harness. This feature allows for launching game rounds with different amounts of delay for each player. Also included is a logging system that captures player data every game tick, provides round summaries, and records details of each projectile shot, facilitating detailed analysis of player performance under different latency conditions. After each round, the game shows customizable qualitative questions to players - the defaults inquires about perceived lag and acceptability. User answers are logged in the round summary.

Configs

Last Stand needs to be configured before experiments are run. At least 2 computers are required to run the game, where 1 will act as server/host and 1 as a client. Inside the Data/ folder there are 3 configuration files.

• Game Config The first GameConfig.csv is for setting the game parameters and takes in 1 row of data, with 5 columns defining the global game configuration: Is Server, IP, Port, Enable Ping Display and Round Duration. This is read from the server and the client.
  • Is Server Value can be TRUE or FALSE, indicating if the game is run in server mode or client mode.
  • IP For the host, it can be kept as 127.0.0.1. For clients, it must be changed to the host's IP address.
  • Port Must be the same on host and clients. By default it is 7777.
  • Ping Value can be TRUE or FALSE. When TRUE the players' current latency is shown in the top center of the screen.
  • Round duration indicates how long each round will last

Example File:

Is Server	IP	Port	Enable Ping Disply	Round Duration
FALSE	127.0.0.1	7777	FALSE	80.0

Here, the config represents a client, connecting to a server running at localhost:7777 and ping will not be displayed. For clients, the round duration is ignored because it is read by the server only.

P.S: The main GameConfig.csv must not have any header, just values.

• The second file PlayerConfig.csv defines the configuration for both of the players' delay settings each round. This is read from the server. It can have n rows, indicating n+1 rounds. The first row of the game is played twice: initially as the 'Practice Round' and then again at a random point in the session. Before each session, the round settings are shuffled to ensure variability in the experiences of the players. This file is read only on the host side and the settings are propagated to the client at the start of each round. There are 8 columns in each row. For the columns, these are:

  • Client 1 base delay,
  • Client 1 target delay,
  • Client 1 adaptive time delay increase rate,
  • Client 1 adaptive time delay decrease rate.

  The next 4 columns are similar, but for the Client 2.

P.S: For latency configurations, set base and target delay the same, increase/decrease rate can be any value.

Example File:

Client 1 base delay	Client 1 target delay	Client 1 adaptive time delay increase rate	Client 1 adaptive time delay decrease rate	Client 2 base delay	Client 2 target delay	Client 2 adaptive time delay increase rate	Client 2 adaptive time delay decrease rate
0	0	2000	2000	0	0	2000	2000
0	0	2000	2000	100	100	2000	2000

Here, the first row is where both of the players have no latency, and second row is where client 1 has no latency but client 2 has 100 ms of latency.

P.S: The main PlayerConfig.csv must not have any header, just values.

• The final config file is called WeaponConfig.csv and this file is read from the client side. Allowing each client to have different weapon properties. takes in 1 row of data, with 4 columns defining the client weapon configuration:
  • Firing type
    • 0 for semi auto
    • 1 for burst of 3
    • 2 for full auto
  • Weapon fire rate (rounds per minute)
  • Magazine size
  • Damage per bullet

Example File:

Firing Type	Fire Rate	Magazine Size	Damage per bullet
2	400	31	3

This represents a fully automatic weapon with 400 RPM fire rate, 31 magazine size and 3 damage per bullet.

P.S: The main GameConfig.csv must not have any header, just values.

Building The Game

The game was developed using Unity 2023.2.1f1 and uses Unity Netcode for Gameobjects alongside FPS Animation package. The full Unity source with all the assets can be found here - https://drive.google.com/file/d/12r7bYfud7ZrPLey-NS9Kxud00wS1jf3i/view?usp=drive_link. Open the repo with the correct version of Unity, then build.

Thesis Report

Last Stand was used as a tool for my M.S. thesis. Details can be found here: Samin Shahriar Tokey. Improving Player Experience and Fairness Using adaptive Time-Delay on First-Person Shooters, M.S. Thesis, Interactive Media and Game Development, Worcester Polytechnic Institute, Summer 2024. (Advisor Mark Claypool) Online at: http://www.cs.wpi.edu/~claypool/ms/tokey-lag-24/